ATTRIBUTE CHARACTERIZATION SCHEMES FOR ANCIENT TEXTILES

Cherilyn N. Nelson and Robert F. Johnson

Introduction.

The basis for this discussion of attribute characterization schemes for ancient textiles is a collection of textile fragments excavated by the University of Minnesota Akhmim project under the leadership of Professor Sheila McNally. Akhmim was chosen for excavation be­ cause the town has been occupied continuously since Pharaonic times or earlier. The site of the modern town of Akhmim (Figure 1) is, therefore, an archaeological tell which has risen for more than four millennia (McNally, 1978/79). Continuous occupation of this site has created the potential to study material culture development through many changes in political culture.

In the four millennia of existence, Akhmim has been ruled by Egyp­ tians, Greeks, Romans, and Arabs. Although the political hierarchy changed many times, the town continued to be known as a center for textile production. Historical references (Strabo, 17.1.41) as well as more recent references (Kendrick, 1920; Falke, 1922; Serjeant, 1948) note the production of linen fabrics, silk fabrics (Falke, 1922; Kiihnel, 1961), wool rugs (Ya'gubi, 1892), and cotton fabrics (Broderick, 1896; Maspero, 1902; Baedeker, 1914; Kendrick, 1920) at Akhmim.

Archaeological evidence of textile production at Akhmim from the Graeco-Roman era through Christian times to the Arab Conquest also exists (Maspero, 1902), and forms the basis for Egyptian textile collections in museums throughout the world (Beckwith, 1959; Robinson, 1969-; Podmore, 1979).

Thus, excavation at Akhmim was expected to produce many textiles. A total of three hundred and eighty-seven samples were collected in and around Akhmim in 1978 and 1981. This collection contains fragments representing the four major natural fiber types, and

ARS TEXTRINA 9 (1988), pp. 11-41

ranges from simple to complex structures with and without color. The time span covered by these samples is roughly from the VI to XIX century A.D. The fragmentary nature and general lack of elaborately woven or embellished samples created the possibility to use these samples to study the development ,of characterization schemes for material attributes in ancient textiles.

Limitations on analysis.

The purpose in analyzing archaeological textiles, or any other ar­ chaeological artifact, is to characterize the artifact in order to de­ scribe the whole of that cultural product or to compare it with simi­ lar products from other cultures. However, there are several limita­ tions on the description of the whole of textiles from any ancient culture.

The first limitation is biased collection. Many Egyptian textiles have been found, but some of the early excavations bordered on plunder (Volbach, 1969), with very little information recorded of the cir­ cumstances in which the textiles were found. More elaborately wo­ ven and sdyed ornamental parts were frequently removed and neither the original garment, nor a record of it was kept (Kendrick, 1920). Also, plain, undyed pieces were rejected. Unsystematic retrieval and selective collection make description of the whole of ancient Egyptian textiles problematic (Rogers, 1983).

A second limitation is the effect of the natural processes of degrada­ tion that can occur during the use life of a textile, during burial, or after excavation.

Pre-burial physical degradation can affect post-burial chemical and biological degradation of textiles. If sufficiently severe, degradation will limit the amount and nature of textile material excavated. It will also limit the amount of information obtained in chemical and physi­ cal analysis of textile attributes. Spurious results due to the alter­ ation or obliteration of unique chemical and physical properties of attributes are a possibility even with relatively skilled analysts.

The description of the whole of ancient Egyptian textiles is further limited by the relative lack of information concerning an analytical

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method for textile characterization. There are many published ac­ counts of attempted analyses of ancient textiles that could be consid­ ered as guides in the examination of such artifacts. However, it is apparent that these have been conducted by individuals with widely differing expertise and opinions as to what constitutes relevant data, and how it can be determined with a reasonable amount of certainty.

For example, yarn count, that is, the number of hanks per pound, was characterized in body wrappings from a cemetery near Meydum in Upper Egypt (Midgley, 1911). There was no indication of the relevance of yarn count in archaeological textile analysis and de­ scription or recognition of variability due to the hand-spinning pro­ cess. Also, changes in yarn count which could result from the weight of soil in burial were overlooked.

Fiber type is a more commonly characterized archaeological textile attribute. In some instances no method for fiber type identification has been indicated (Kendrick, 1920; Crowfoot, 1977). In others, the methods range from low level magnification (Bellinger, 1950, 1952, 1955, 1957; Baginski & Tidhar, 1980), to optical microscopy (Lamm, 1937; Appleyard & Wildman, 1963), to polarized light mi­ croscopy (Rose & Dietze, 1978), to a combination of optical, polar­ ized, and scanning electron microscopy (Fiedler, 1979), or a combination of optical microscopy and staining (Benson, Hemingway, & Leach, 1979).

Dye is another commonly characterized archaeological textile at­ tribute. Like fiber type, the method of identification for dyes ranges from not being specified (Kybalova, 1967), to the use of spot tests which produce a color change (Granger-Taylor, 1979), to thin-layer chromatography (Masschelein-Kleiner & Macs, 1979) to spec- trophotometric analysis (Saltzman, 1963), to ultraviolet and infrared spectroscopy (Masschelein-Kleiner, et a/., 1979) and Xrray diffrac­ tion (Rose, et al., 1978).

Although many different analytical techniques have (been used, there is a general lack of consideration of tiffi relevance of specific at­ tributes as well as the level of analysis necessary and sufficient for archaeological textile description. Also, only a limited number of

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analysts (Appleyard, et al., 1963; Baginski, et al., 1980) recognized the possibility of spurious results which could be attributed to the effects of degradation.

Characterization scheme development.

The accurate description and comparison of the whole of textile arti­ facts from any culture requires that the methodology of analysis eliminate as many sources of error as possible. While limitations due to biased collection and degradation are difficult to control, lim­ itations due to methodology of analysis can be more easily elimi­ nated. In establishing a methodology of analysis, careful considera­ tion must therefore be given not only to the selection of attributes or distinctive artifact features for analysis, but also to an appropriate level of analysis for their characterization.

Attribute selection. George Nelson (1979) noted that in prein- dustrial technology the design and the making of an object were in­ separable. With the Industrial Revolution and concomitant special­ ization, it became possible to separate process from object. Thus, the object could be evaluated in terms of materials, the tools used to make it, social taboos associated with the object, and even cost.

In that statement, Nelson is referring to the analysis of groups of at­ tributes. Attributes are distinctive features or properties of an arti­ fact that have been determined to be relevant and indispensable in description of the artifact.

These attributes can be grouped on the basis of commonality, and complete description of an artifact would require description of all attribute groups that have been determined to be relevant.

The first step in the analysis of archaeological textiles requires the selection of indispensable attributes for analysis. Indispensable at­ tributes are those that are necessary, sufficient, and relevant to the description of the whole of textiles produced by a culture. The at­ tributes selected must allow their combination with other indispens­ able attributes, for it is through the establishment of attribute rela­ tionships that cultural information can be obtained.

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From the published descriptions of archaeological textiles, it is ap­ parent that attributes selected for analysis fall into three groups: aesthetic; function; and material. Individual descriptions differ in which of the three groups were analyzed, as well as specific at­ tributes included for analysis. Even if all three groups had been an­ alyzed, the textile descriptions would not be complete because they would lack inclusion of all indispensable attributes.

Indispensable attribute groups for the Akhmim collection were de­ termined to be aesthetic, function, technique, and material. In the ideal situation, analysis of specific attributes from each group would permit complete archaeological textile description and ultimately cultural comparison. In reality, this is difficult to accomplish.

The fragmentary nature of many archaeological textiles would affect the likelihood that aesthetic attributes, for example, subject, config­ uration, organization, pattern repeat, clarity of outline, and spatial appearance of the design (Farrell & Lapitsky, 1978; Kwon, 1979), or function attributes, for example, use, shape, and dimensions could be accurately characterized. Written documentation of identical ar­ chaeological textiles may provide necessary corroborative evidence.

An additional problem exists for function attributes, namely, the dis­ tinction between intended and actual function. For example, it is known that the blue and white checked shawls manufactured at Akhmim were worn by poorer classes for state occasions (Broderick, 1896). The intended function could, therefore, be cer­ emonial dress. However, these same textiles were torn in half to be used as bindings for corpses making the actual function very differ­ ent from the intended function. The characterization of intended or actual function is an issue that has not yet been resolved by archae­ ologists, but is one about which textile analysts should be aware.

Technique attributes which include the processes and equipment used to manufacture a fabric cannot be directly and independently de­ duced from fabric appearance because almost any textile structure could be achieved by different procedures (King, 1965; Emery, 1980). Without excavation of the actual equipment, determination of technique is dependent on documentation in literature. However,

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these descriptions need to be read critically for use of terminology and feasibility of claims.

Material attributes, for example, fiber type, yarn structure, fabric structure, dye and mordant, can generally be analyzed if textile fragments are large enough and not so degraded as to preclude analysis.

Level of analysis. A related problem to the selection of at­ tributes is level of analysis (Figure 2). As sophistication in analysis increases from macroscopic to microscopic to chemical, so also does the requirement in terms of equipment and analyst skill. Although higher levels of analysts give more data on a textile, that data may not be particularly useful or relevant in textile description and cul­ tural comparison. For example, elemental analysis of fibers will not necessarily provide useful information for describing and comparing textile materials among cultures.

Conversely, a higher level of analysis may be necessary in order to obtain information not available at some lower level. While a stereomicroscope can be used to definitely establish fabric and yarn structure, it cannot generally provide unequivocal fiber type identi­ fication. Depending on fiber type, higher levels of magnification with light microscopy or polarized light microscopy may be re­ quired before type can definitely be established. Even with higher levels of magnification, the analyst will need to determine whether longitudinal or cross-sectional fiber views are necessary for identi­ fication and whether this level of analysis is sufficient.

Regardless of the level of analysis, understanding methodological limitations as well as process technology, terminology, and analytical techniques is a necessary analyst skill. Thus, spurious results due to lack of specificity in an analytical technique, or use of incorrect an­ alytical techniques can be avoided. This is a critical factor in the de­ sign of a characterization scheme for the analysis of archaeological textiles.

Characterization schemes. Determination of indispensable at­ tributes and the necessary level of analysis are the two components of a characterization scheme (Figure 2). The scheme may be elaborate,

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requiring many steps, or the use of sophisticated equipment to de­ termine a result. Conversely, it could be very simple but depend too heavily on a single test or tests which are not sufficiently accurate or precise, creating the possibility of spurious results. Ideally the char­ acterization scheme would involve analysis at as low a level as con­ sistent with accurately characterizing textile artifacts, so that it could be practiced in a larger number of contexts.

The fragmentary nature of the Akhmim collection and the lack of elaborately woven or embellished samples precluded extensive analysis of aesthetic and function attributes. Lack of written ac­ counts of Akhmim textile manufacturing precluded analysis of tech­ nique attributes. However, the collection was used to design charac­ terization schemes for the analysis of material attributes with special emphasis on fiber type, dye, and mordant because these attributes are among the most difficult to characterize

Fiber type characterization scheme.

There are many physical, chemical, and mechanical properties that may characterize fibers. Mechanical properties are related to textile performance in various situations and are generally irrelevant to fiber identification. Fiber identification could, therefore, be accom­ plished by analyzing relevant physical and chemical properties. The usefulness of a property for fiber type characterization is dependent on the state of preservation of the textile as well as its specificity. A property which exhibits for one fiber type a range of values over­ lapping those of another fiber type is limited in application to fiber identification.

Of the properties shown in Table 1 there were several that could be used in a characterization scheme to identify natural fibers. The complexity of the scheme will depend on the level of description necessary for cultural comparison. Thus, if it is sufficient to identify natural fiber type only as cotton, bast, silk, or wool, the scheme would end with light microscopy of surface morphology.

However, the possibility of determining specific bast or wool fiber would require additional steps. Identification of specific wool fiber type has been attempted by examination of many properties including

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surface morphology, birefringence, pigmentation, and fiber diameter (Fiedler, 1979) with limited success. References to the use of bast fibers other than flax (Herodotus, LXXIV; Forbes, 1956) suggest that identification of specific bast fiber would be a relevant attribute.

Additional steps to identify flax, ramie, jute, or hemp are shown in Figure 3. Rotation on drying, a property dependent on the spiraling direction of the most prominent fiber fibrillar layer, would separate flax and ramie (clockwise rotation on drying) from jute and hemp (counter-clockwise rotation on drying). Since fiber degradation would affect propensity to rotate on drying, results from this ana­ lytical technique could be corroborated with retarded polarization color behavior.

Fibers viewed through the dark field of crossed polars exhibit colors that appear in a characteristic color order sequence divided at reg­ ular intervals by different intensity reds. A change in order, that is, a change in intensity, is apparent on rotation and can be used to identify some fibers. Rax and ramie would show similar results going from less intense to more intense colors, or from a higher or­ der to a lower order. Jute and hemp would also show similar results going from more intense to less intense colors, or from a lower order to a higher order.

Finally, transverse shape might be used to determine specific bast fiber type. This would require an appropriate reference set for comparison of transverse shapes to prevent spurious bast fiber identification.

Fiber types in the Akhmim textiles.

Microscopic examination of surface morphology. Fiber types identified by Step 1, the microscopic examination of surface morphology, are shown in Table 2. Totals are based on the exami­ nation of eighty-five samples from 1978 and three hundred and two samples from 1981. In general, cellulose fiber samples were more prevalent, and were found in three hundred and thirty-one samples compared to ninety-seven samples with protein fibers. These num­ bers include fabrics made wholly of yarns of one fiber type and fab­ rics which were made from combinations of yarns of different fiber

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types, for example, a combination of bast yarns and cotton yarns, denoted in Table 2 as bast/cotton.

Given the time span of the Akhmim textiles, there could be definite chronological trends in fiber types used in fabrics that reflect eco­ nomic, religious, and political changes in Egyptian society. For ex­ ample, ancient Egyptians were known to have used wool fibers, but their religion forbade the burying of wool fabrics with bodies. Thus, there was a lack of wool fabrics in very early burials. Wool fabrics became more prevalent in late Roman and Coptic burials as evidenced by the large number of wool tapestry inserts and rep wo­ ven bands from the fourth century to eighth century Coptic period in museums throughout the world today. From the seventh century, the Muslims continued to use the wool industry established by the Ro­ mans and built a strong wool weaving industry in the Middle Ages. Therefore, the increase in the use of wool in fabrics also should be reflected by an increase in the number of wool fabrics found in later Egyptian burials.

A similar argument can be made for silk fabrics which were rare in ancient Egypt and restricted to wealthier classes. However, the in­ troduction of sericulture in Egypt in the sixth century A.D. should have increased the amount of silk available for Egyptian society. Silk yarns combined with yarns from other fiber types in fabrics lowered the cost of production and made at least part silk fabrics available to less wealthy individuals. These changes should be apparent in an increase in the number of wholly silk or partially silk fabrics found in later burials. Despite this, the use of silk in general could not be expected to be as prevalent as other fiber types, espe­ cially cellulose.

The majority of fabrics in ancient Egypt were produced from cellu­ lose fibers. Ancient Egypt was especially known for the manufac­ turing of linen fabrics from flax. In addition to linen fabrics recov­ ered from tombs, hieroglyphics on monuments show linen fabric manufacturing was a well developed trade. There are many refer­ ences in written records to linen cloth and clothing, as well as to the quality or texture of the cloth.

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Some of the linen produced was traded for Indian cotton fabrics or fibers which were considered a luxury good. As with other new luxury goods, these were reserved for sacred-purpose fabrics (Pliny, XIX, Ch. 14). Cotton fiber was also used to make embroidery thread for embellished fabrics. Eventually, the Romans established a cotton manufacturing industry in Egypt. However, the small amount of cotton fiber grown for local use was low in quality. Thus, cotton yarn was frequently used as the filling in fustian fabrics with flax warp yarns or in mulham fabrics with silk warp yarns; both of these warps were considered stronger than cotton warp (Pliny, XIX, Ch. 14). Additionally, mixing cotton with some fiber types in fabric could have had an economic basis similar to silk. Cotton was even­ tually cultivated as a major crop, although it is not likely that that occurred until after the Arab conquest in the seventh century; it was a well established industry from the twelfth century A.D. (Lamm, 1937). The increase in the use of cotton was coupled with a decline in the use of flax. This should be reflected in an increase in the number of cotton samples in later burials.

Some of these general chronological trends in fiber type usage could be observed in the Akhmim textiles for those samples which could be assigned a date range on the basis of location, that is, from the Monastery of Martyrs or from Abu Seiffein. Burials at the Monastery of the Martyrs occurred from the fourth century to the eighth century, while burials from Abu Seiffein were from the sev­ enteenth century to the nineteenth century. It is possible to make tentative comparisons of frequency of fiber type occurring at the earlier Monastery of the Martyrs site to the later Abu Seiffein site.

For example, those samples in which the prinicpal fabric was wholly silk fiber should be more prevalent in later burials. In fact, the per­ cent of silk fiber samples from the Monastery of the Martyrs with respect to all samples from that site, when compared to the percent of silk fiber samples from Abu Seiffein with respect to all samples from that site, increased from one point one percent to eleven point eight percent. Wool fiber samples would be expected to show a sim­ ilar increase. However, wholly wool fiber fabrics decreased from four point five percent of the Monastery of the Martyrs samples to

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two point eight percent of the Abu Seiffein samples. Although thirty point three percent of the Monastery of the Martyrs samples con­ tained rep woven wool fiber band elements in a bast fiber fabric, there was no similar fabric from Abu Seiffein, thus, precluding trend analysis.

Bast fiber and cotton fiber should show an indirect relationship when earlier and later burials aie compared; this trend was apparent. Bast fiber samples decreased from fifty-eight point four percent of the Monastery of the Martyrs samples to sixteen point four percent of the Abu Seiffein samples. Conversely, cotton fiber samples in­ creased from four point five percent of the Monastery of the Mar­ tyrs samples to forty-five point six percent of the Abu Seiffein samples.

Silk fiber in combination with other fibers, similar to wholly silk fabrics, should show an increase in later burials. There were no such samples at the Monastery of the Martyrs, but five point two percent of the Abu Seiffein samples were silk fiber and other fiber combinations. Cotton fiber and bast fiber combinations would be expected to show no changes because of the previously established relationship. However, there were no such samples from the Monastery of the Martyrs compared to six point three percent of the Abu Seiffein samples.

An extensive examination of frequency of fiber type by date in the Akhmim textiles, and comparison of this to the general chronological trends, must await the specific dating of the textiles on the basis of dated, adjacent non-textile artifacts. These non-textile artifacts are now in the process of being dated.

Bast fiber type determination. One hundred and fifty-two bast fiber samples were identified by microscopic examination of surface morphology. These were further analyzed according to Figure 3, by determining rotation direction on drying, retarded polarization color behavior, and transverse shape in an attempt to distinguish between flax, ramie, jute, and hemp fibers.

According to the literature, the prominent, 5-oriented second layer of flax and ramie causes those fibers to rotate clockwise on drying,

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while the prominent, Z-oriented outer layer causes jute and hemp to .rotate counterclockwise (Roelofsen, 1951; Luniak, 1953). Only two samples rotated counterclockwise as jute or hemp would rotate. The remainder rotated clockwise as flax or ramie.

Generally, finer fibers rotated more rapidly than coarser fibers. More observations were required to determine the rotation direction of fibers from degraded samples. Disintegration of fibrillar layers affected the propensity of a fiber to rotate, that is, the number of rotations and the speed of rotation. However, it was possible to find fibers from degraded samples which would rotate, even if more slowly and for fewer rotations. Apparently the degree of fibrillar disintegration is more critical in determinating number of rotations and the speed of rotation than age since some fibers from Monastery of the Martyrs samples rotated more and more rapidly than fibers from some Abu Seiffein samples.

Stiff samples, or samples covered with what appeared to be a resin coating, were not as likely to rotate. However, selection of yarns from softer, more flexible areas in those samples provided fibers that would exhibit some propensity for rotation. The presence of dye did not appear to affect propensity for rotation.

Results of the fiber rotation test were corroborated by examining the behavior of retarded polarization colors. Rax/ramie samples exhib­ ited more intense, lower order colors while jute/hemp exhibited less intense, higher order colors. Change in specific color order varied with individual fibers and samples; however, the addition or sub­ traction of color order corroborated fiber rotation results.

A subsample of the bast fiber population was selected for analysis of transverse shape by Step 3 of Figure 3. These specimens were em­ bedded in Spurr's resin, cross sectioned, and viewed at 400X magni­ fication in unpolarized light on the Nikon S-Ke microscope. Samples of contemporary jute, hemp, ramie, and flax were also embedded and cross sectioned for use as a reference set. Additionally, pho­ tomicrographs from Luniak and the American Association of Textile Chemists and Colorists were used for reference. Specific bast fiber type as determined from transverse shape is shown in Table 3. The

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number of samples in Strata 4 and 5 were higher than required by the sampling process in order to include analysis of three, more unique samples. These were the two samples previously identified as jute/hemp, and one sample in Stratum 4 with fibers that appeared to be longer than most of the other bast fibers.

On the basis of lumen size and shape, and fiber shape, eighteen flax, six ramie, and two jute samples were identified. These identifica­ tions are tentative, however, for several reasons.

First is the possibility of incorrectly identified contemporary fibers. A case in point is the current interchangeable naming of flax and ramie. In fact, the contemporary reference sample thought to be ramie looked more like flax when compared to photomicrographs. Thus, reliable sources of reference fibers is an absolute necessity.

Even with reliable sources, contemporary commercial fibers for reference may be of limited use for meaningful comparisons with certain attributes of archaeological fibers. While identification of broad classes of historic fibers, that is, wool or bast, is not likely to be a problem, identification of fiber types within those classes may be more problematic. More significant comparisons may be possible with contemporary fibers taken from primitive cultigens and their wild relatives (Stephens, p. 310). Fibers collected from less devel­ oped countries may also provide more suitable reference specimens.

Finally, the photomicrographs selected for comparison will influence identification of specific bast fiber type. Lack of consistency in fiber appearance among different photomicrographs for the same fiber type makes the possibility of correct identification tenuous.

Dye and mordant characterization scheme.

Various properties that could be useful in dye analysis are listed in Table 4. Color was eliminated because of the lack of specificity. Many ancient textiles were dyed with mordant dyes which require metals to affix the dye to fiber. These dyes can produce different colors with different mordants on the same fiber type. Also, the same dye with the same mordant can produce different colors on different fiber types. Therefore, dye application class, dye and

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mordant were combined in the characterization scheme shown in Figure 4. The scheme incorporates analysis of a sufficient number of properties at as simple a level as possible.

In the first step, Clayton scheme reagents (Oaytoit, 1963) could be used to determine empirical color changes on dyed fibers which could be used to indicate one of three probable dye application classes for natural dyes. A reference set of known dyes and known mordants on known fibers would also need to be subjected to the scheme for comparison with the archaeological fibers analyzed.

While the Clayton scheme can distinguish direct, vat, and mordant dye application classes, it must be remembered that synthetic dyes with structures and properties similar to natural dyes may produce similar color changes leading to potential difficulties in distinguish­ ing synthetic and natural dyes. The Clayton scheme will definitely identify natural mordant and vat dyes but may confuse the identifi­ cation of synthetic acid dyes and direct dyes. Given the time span of the Akhmim collection, the presence of synthetic dyes was a distinct possibility.

Thin layer chromatography in the second step would identify those dyes whose application class was determined by Step 1 to be direct or mordant. This technique is suitable for relatively small quantities of dye and can be used effectively with a sufficiently adequate reference set.

In the third step, x-ray microprobe can be used to identify metallic mordants on those dyes determined to be mordant. A reference set of known mordants on known fibers is necessary to determine whether elevated element intensities were due to the presence of mordants or some other source such as soil or degradation products.

Dyes and mordants identified.

Dye application class determination. A subsample of the dyed Akhmim textiles (Table 5) was subjected to Clayton scheme reagents to determine the feasibility of that scheme for identifying archaeo­ logical dye application class. Seventeen blue dyed cotton, flax/ramie, silk and wool samples treated with sodium dithionate were identified

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to have a vat dye, specifically indigo. However, reoxidation to blue was difficult to detect on those samples with small quantities of dyes present. Also, the presence of a second dye cm samples precluded the detection of a vat dye. For fliose samples, vat dye application class was determined with glacial acetic acid which dissolves indigo dye in particular to a blue solution.

Ten red dyed cotton, flax/ramie, silk and wool samples were sub­ jected to Clayton scheme reagents. Three dye application classes, vat, mordant, and azoic, were 'identified.

Reoxidation of five samples to very light colors following treatment with sodium dithionate indicated the presence of vat dyes. This was confirmed with ethlenediamine and vat dye developer. Two samples were identified to have & mordant dye because treatment with sodium dithionate produced a color different than the original, a character­ istic reaction for most mordant dyes. Three samples were identified to have azoic dyes because of their irreversible reduction with sodium dithionate. Although azoic dyes were not introduced until 1880, and then only one - Para Red - was in use until others were introduced in 1911 (Johnson, Zenhausern, & Zollinger, 1963), it is possible some of the Akhmim textiles were recent enough to utilize these dyes. The recent nature of these samples was confirmed by the presence of printed designs and plastic buttons.

The five yellow and orange dyed samples subjected to Clayton scheme reagents showed one sample to have a direct dye and four to have a mordant dye. The direct dye became progressively lighter with each reagent that was used; the mordant dyes produced the characteristic permanent color change with sodium dithionate.

Thin layer chromatography. All dyes identified as mordant and direct were extracted, spotted on polyamide thin layer chromatogra­ phy plates, and developed in saturated chambers (Schweppe, 1975). One yellow sample was identified as most likely being turmeric. Identification of this sample as turmeric is supported by Clayton scheme color reactions which were similar to the reference turmeric. None of the red samples could be identified.

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While thin layer chromatography is an acceptable method for deter­ mining specific dye, there are several important factors which affect results and ultimately the identification of dye type.

The first factor is the eluent choice. The eluent must be sufficiently polar to separate components, but not so polar that it prevents ab­ sorption of components on the plate. The eluent used in this study was described as being suitable for a wide range of natural dyes, but it had little utility for the unknown dyes in this study. While the possibility of synthetic dyes being used should not be overlooked, neither should the possibility of natural dyes sufficiently different in chemical structure so that an eluent of general utility is not feasible. Thus, it would be necessary to establish a broader range of eluents suitable for specific natural dye chemical classes.

A second factor is the presence of impurities in the dye. Archaeo­ logical textiles are very likely to introduce impurities because of the soil and organic matter that may be in the fabric. While these theo­ retically should be separated from the dye by thin layer chromatog­ raphy, it is possible that they can somehow combine with the dye molecule, therefore, causing hRf values and colors that differ from the dye itself.

Additionally, the dye may not be completely demetallized in the ex­ traction process. The dye/metal complex would likely show a different hRf value in its own right, but could also affect the elution rate by attracting interfering impurities to the complex. Conversely, the extraction process could be sufficiently severe to alter the molecular structure of the dye, leaving degradation products for analysis by chromatography.

A final factor is the possibility of slightly different species of plants or insects which would produce chemically different dyes; these components could exhibit different hRf values and colors.

Mordant determination. Four millimeter squares of dyed ar­ chaeological fabric or lengths of dyed archaeological yarn that had been washed in distilled water were mounted on stubs with spectra grade carbon paste. The mounted samples were stored in a dessica- tor for twenty-four hours before coating with vaporized carbon and

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nickel in a vacuum evaporator. Following coating the samples were analyzed for one hundred seconds by a beam current on the scanning electron microscope that had been standardized every ten spectra at three thousand aluminum counts/second using the carbon paste-free part of the stub.

Intensities were collected for elements that were determined to be indicator elements for possible mordants, that is, aluminum, potas­ sium and sulfur for an alum mordant; copper and sulfur for a copper mordant; iron and sulfur for an iron mordant; and tin and chlorine for a tin mordant; silicon was also determined (Nelson, 1986). El­ ement values collected from the red, yellow, and orange dyed ar­ chaeological fibers were compared with element values obtained from unmordanted contemporary fibers; unmordanted, unwashed archaeological fibers; unmordanted, washed archaeological fibers; and mordanted,undyed archaeological fibers. Element values from like fiber types were compared.

The Clayton scheme had identified six samples as having a mordant dye; however, only two of those samples were identified as having an iron mordant by x-ray microprobe. Results for the remaining four samples were inconclusive.

Although x-ray microprobe is an acceptable technique for mordant determination, bias can be introduced into the results if soil and fiber degradation products are present. Also, contemporary reference fibers from geographic contexts different than those fibers being analyzed may bias the determination. A significant difference was found between indicator element values for contemporary and archaeological fibers that may challenge the use of contemporary fibers as references in those instances where lack of similarity be­ tween contemporary and archaeological attributes may exist (Nelson, 1986).

Conclusion.

As is true of other archaeological artifacts, textiles are useful in de­ scribing cultural continuity or change. They can indicate the level of technical development of a given culture, as well as contact with other cultures, especially when nonindigenous materials, techniques,

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or designs are identified as attributes. Thus, it is critical that accu­ rate analysis be conducted. The analysis of archaeological textiles requires the establishment of indispensable attributes and characteri­ zation schemes which will eliminate potential sources of error.

However, in addition to identifying sources of error in characteriza­ tion schemes, the level of data necessary for textile description and comparison must also be identified. For example, few would argue the relevancy of fiber type, but the need to determine specific type, such as flax or ramie within the general bast fiber group may be questioned because of the difficulty in distinguishing the two fiber types. Additionally, the possibility of happenstance discovery and use of bast fibers similar to flax may make detailed analysis unnecessary.

Finally, the nature of the reference set is a factor that also needs consideration, especially in those instances where lack of similarity between contemporary and ancient textile attributes may exist. If suitable reference sets cannot be established for attribute analysis, an analyst would need to determine the need for characterizing such attributes.

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References

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6. L. Bellinger, Textile analysis: Early techniques in Egypt and the Near East, Washington, DC: The Textile Museum, Workshop Notes No. 6 (1952).

7. L. Bellinger, Textile analysis: Pile techniques in Egypt and the Near East, Washington, DC: The Textile Museum, Workshop Notes No. 12 (1955).

8. L. Bellinger, Textile analysis: Developing techniques in Egypt and the Near East, Washington, DC: The Textile Museum, Workshop Notes No. 15 (1957).

9 - G.G. Benson, S.R. Hemingway and F.N. Leach, The analysis of the wrappings of mummy 1770,. in "The Manchester Museum Mummy Project", Ed., A.R. David. Manchester, England: The Manchester University Press, 1979.

10. M. Broderick, "A Handbook for Travellers in Lower and Upper Egypt", London: John Murray, 1896.

11. E. Clayton, "Identification of Dyes on Textile Fibres. Second Edition", Dean House, Piccadilly, Bradford, England: The Society of Dyers and Colourists, 1963.

12. E. Crowfoot, Textile finds from Qasr Ibrim: A preliminary note, Journal of Egyptian Archaeology 63 (1977), 45-47.

29

13. I. Emery, "The Primary Structure of Fabrics. Second Edition", Washington, D.C.: The Textile Museum, 1980.

14. O.V. Falke, "Decorative Silks", New York: William Heburn, Inc., 1922.

15. J.A. Farrell and M. Laptisky, Aesthetic and structural characteristics of selected woven silks with emphasis on Dutch silks of the seventeenth century, Home Economics Research Journal 6 (4) (1978), 254-261.

16. I. Fiedler, The fibers., in "Ancient Textiles from Nubia", Eds., C.C.M. Thurman and B. Williams. Chicago: The Art Institute of Chicago, 1979.

17. RJ. Forbes, "Studies in Ancient Technology. Vol. IV", Leiden: E.J. Brill, 1956.

18. H. Granger-Taylor, Coptic textiles, in "Ancient Coptic Textiles", Ed., C. Rogers. Brighton, England: Rogers and Podmore, 1979.

19. Herodotus. Translated from the original Greek by the Rev. W. Beloe, "The Ancient History of Herodotus. Book IV: Melpomene", New York: Derby and Jackson, 1959.

20. R.F. Johnson, A. Zenhausern and H. Zollinger, Azo dyes, in "Kirk-Othmers Encyclopedia of Chemical Technology 2, Second Edition", Ed., A. Standen. New York: Wiley- Interscience, 1963.

21. A.F. Kendrick, "Catalogue of Textiles from Burying Grounds in Egypt, Vol I: Graeco-Roman Period", Victoria and Albert Museum, 1920.

22. M.E. King, "Textiles and basketry of the Paracas period, lea Valley, Peru", Doctoral dissertation, University of Arizona: Tuscon, 1965.

23. E. Kuhnel, The rug tiraz of Akhmim, Workshop Notes, Paper 22. Washington, D.C.: The Textile Museum, 1961.

24. Y-H. Kwon, Changing function of symbolism in design of Korean silk textiles, Home Economics Research Journal 8 (1) (1979), 17-26.

25. L. Kybalova, Coptic textiles, London: Paul Hamlyn, 1967.26. C.J. Lamm, "Cotton in Mediaeval Textiles of the Near East",

Paris: Librairie Orientaliste Paul Geuthner, 1937.

30

27. B. Luniak, "The Identification of Textile Fibres, Qualitative and Quantitative Analysis of Fibre Blends", London: Sir Isaac Pitman & Sons, Ltd., 1953.

28. SJ. McNally, Excavations at Akhmim, Egypt: 1978, American Research Center in Egypt, Inc. Newsletter 107 (1978/79).

29. G. Maspero, "Manual of Egyptian Archaeology and Guide to the Study of Antiquities in Egypt", translated by A.B. Edwards. London: H. Grevel and Co., 1902.

30. L. Masschelein-Kleiner and L.R J. Macs, The dyes, in "Ancient Textiles from Nubia", Eds., C.C.M. Thurman and B. Williams. Chicago: The Art Institute of Chicago, 1979.

31. W.W. Midgley, Linen of the IIIrd Dynasty, in "Historical Studies" 2, Eds., E.B. Knobel, W.W. Midgley, J.G. Milne, M.A. Murray and W.F. Petrie. London: British School of Archaeology in Egypt, 1911, 37-39.

32. C.N.S.N. Nelson, "A methodology for examining ancient textiles and its application to VI-XIX century textiles from Akhmim, Egypt", Ph.D. thesis, University of Minnesota: St. Paul, 1986.

33. G. Nelson, "Design", London: The Architectural Press Ltd., 1979.

34. Pliny. Translated by J. Bostock and H.T. Riley, "The Natural History of Pliny", London: Henry G. Bohn, 1856.

35. P. Podmore, The Copts history, in "Ancient Coptic Textiles", Ed. C. Rogers. Brighton, England: Rogers and Podmore, 1979.

36. S. Robinson, "A History of Dyed Textiles", Cambridge, MA: The MIT Press, 1969.

37. P.A. Roelofsen, Contradictory data on spiral structures in the secondary cell wall of fibers of flax, hemp, and ramie, Textile Research Journal 21 (1951), 412-418.

38. C. Rogers, Ed., "Early Islamic Textiles", Brighton, England: Rogers and Podmore, 1983.

39. C. Rose and E. Dietze, Examination and stabilization of two bull mummies: Preserving archaeological evidence of Egyptian rituals/technology, Technology and Conservation (1978 summer), 32-38.

31

40. M. Saltzman, The identification of colorants in ancient textiles, Dyestuffs 44 (8) (1963), 241-251.

41. H. Schweppe, Nachweis von Farbstoffen auf alien Textilien, Zeitschrift fur Analytische Chemie 276 (4) (1975), 291-296.

42. R.B. Serjeant, Material for a history of Islamic textiles up to the Mongol conquest, Ars Islamica XIII/XIV (1948), 75-117.

43. S.G. Stephens, The botanical identification of archaeological cotton, American Antiquity 35 (3) (1970), 367-370.

44. Strabo, "The Geography of Strabo", translated by H.L. Jones. New York: G.P. Putnam's Sons, 1932.

45. W.F. Volbach, "Early Decorative Textiles", translated by Y.Gabriel. The Centre, Feltham, England: Hamlyn Publishing Group Limited, 1969.

46. Ya'gubi, Kitab al-Boldan, Bibliotheca Geographorum Arabicorum VII (1892), Ed. M.J. de Goeje, 332.

Cherilyn N. Nelson Department of Apparel Textiles and Interior Design North Dakota State University Fargo, ND 58105

Robert F. Johnson Department of Design Housing and Apparel University of Minnesota St. Paul, MN 55108

32

Figure 1. Map of Egypt

33

LE

VE

L

OF

AN

AL

YS

IS

CH

EM

ICA

L

MIC

RO

SC

OP

IC

MA

CR

OS

CO

PIC

AE

ST

HE

TIC

FU

NC

TIO

NT

EC

HN

IQU

E

MA

TE

RIA

L

AT

TR

IBU

TE

S

Figu

re 2

. C

hara

cter

izat

ion

sche

me

com

pone

nts

Fiber To Be Identified

Step 1.

Longitudinal surface

morphology by

light

microscopy

Wool

Silk

'Cot

ton

Bast

Step 2.

Kibrillar spiraling

by visual assessment

or fibn rotation and

retarded polarization

color behavior by

polarization microscopy

Step 3.

Transverse shape by

light microscopy

Flax

an

d Kamie

Jute

and

Kta

xK

amie

rJu

t i

Hum

p

Figu

re 3

. A

rcha

eolo

gica

l fib

er id

entif

icat

ion

sche

me

Dyed Fiber

Stc|>

I .

Solubility by

Clayton sc

liem

u

Direct Dy

e Class

Stop 2.

Reversible reduction

by Clay ton

scheme

Vat

Dye

Class and Mordant Dy

e Class

I 1

Val

Uye

Class

Mordant Dy

e Class

Thin la

yi^r

chrom

of dye solut ion

IDirect Dy

e

Dyed fiber Va

t Dye

Murdanl Dy

e

X-ray microprube

analysib of

dyed fiber

I AI

Dyfcd

Fiber

Sn«.•

t c

Figu

re 4

. D

ye a

pplic

atio

n cl

ass;

dye

and

mor

dant

iden

tific

atio

n sc

hem

e

Physical Chemica I '_evel and Method of Anaivsis

Density Length

Diameter

Morphology

- longitudinal surface

- fibrillarspiraling

- transverseshape

Crys tallini ty

- polarization colors

- refractiveindex and birefringence

- degree of order

ChemicalComposition

- burningreaction

- solubility

- staining

- spectrochemical a na ly s i s

Macroscopic: Volumetric analysis Macroscopic/Microscopic:

Calibrated scale Microscopic: Calibrated scale

Microscopic: Compound light,polarized light, and scanningelectron microscopy

Macroscopic: Visual assessment offiber rotation

Microscopic: Compound light,polarized light, and scanningelectron microscopy

Microscopic: Compound light,polarized light, and scanningelectron microscopy

Microscopic: Polarized lightmicroscopy

Microscopic: Polarized lightmicroscopy

Microscopic: X-ray diffraction

Chemical/Macroscopic: Visual andolfactory assessment

Chemical/Macroscopic: Visualassessment

Chemical/Macroscopic: Visualassessment

Chemical/Microscopic: X-rayfluorescence; infrared andultraviolet spectroscopy

Table 1 Physical and chemical properties of fibers

37

oo

Oth

er

1 O

ther

2 B

ast/

Bast/

Bast/

Str

atu

m

Woo

l S

ilk

Cotton

Ba

st

Ce

llu

lose

P

rote

in

Cotton

Woo

l .S

ilk

1. 2.

3.

4.

5.

6.

7.

Abu

S

elffe

ln,

0

1 14

29

8

5 600

1978.

Und

yed

Abu

S

elfle

ln,

06

3

10

0 0

10

0

1978.

Dye

d

Abu

S

elfle

ln.

5 4

6J

4 I8

3 3

50

0

1981.

Und

yed

El

Se

lan

on

ah

, 0

00

73

0

00

0

1981,

Und

yed

Monast

ery

of

1 0

0

45

1 0

00

0

Mart

yrs

, 1981,

Undye

d

Abu

S

elffe

ln,

4 23

51

4

0

0 601

1981,

Dye

d

Monaste

ry of

31

47

0

00

27

0

Mart

yrs

, 1981,

Dye

d

To

tal

12

3?

135

106

3O

8 18

27

1

Co

tto

n/

SI

Ik 1 0 10 0 0 3 0 14

1 In

clu

de

s

Ph

oe

nix

d

acty

llfe

ra

(dote

p

al*

) fiber

an

d U

cepera

ta cyln

drlca

fiber.

5 In

clud

ss on*

Modern sa«pl« trow

th

e city of

Ak

hml"

. Tab

le 2

Fi

ber t

ypes

iden

tifie

d in

the

Akh

mim

text

iles

1 .

2.

3.

4.

5.

6.

7.

TOTAL BAST POPULAT 1 ON

Samp!** In (of Stratum Stratun Total

Abu Silf f *ln, 32 211973. Undy*d

Abu Sfjlf fell), II 71978, Dy.d

Abu S* 1 f f • 1 n , 14 91981, Undy.d

El Salaoonah, 3 51981, Undy*d

Monastery o( 71 47Martyrs, 1 981 ,Undy.d

Abu S.IM.In, 9 61981, Oy*d

Monastery of 7 5Martyri, 1981,Dy.d

SUB5AMPLE

Locus

1 .2.261.2.311.2.321 .2.341 . 2.38

1 .2.261.2.32

1 . sur f ac*1 .2. 1 1 1

1 1 .xl 1 1. turf act1 1 . x I v. sur f ac*1 l.xlv.surfac*

1 .x.su^fac*1 . x. sur f ac»1 . x. sur f ac*1 . x . sur f ac*1 « x. sur f ac«1 . x. surf ac*1 . x. sur f ac*1 .x.sjrf ac>.NEB21 .x.surfao.NUBI1 . x. sur<ac».SUA21 . x. surface. SHA1

1 .2. 1061.1.167

1 1 . x. surf «c«.SKA1

T.xtl It Number

3350546778

2860

72244

7208A202

203640

4276

20020121 1218226B234

175255A

19

Flbtr Type

Flaxf laxFlaxFlaxFlax

FlaxFlax

FlaxRa m !•

Flax

Ra*l«Jut*

FlaxJut*Rani*FlaxFlaxFlaxRant*Rani*Rani*FlaxFlax

FlaxFlax

Flax

Table 3 Specific bast fiber determined by transverse shape

39

Physical Chemical Level and Method of analysis

Color Macroscopic: Visual assessment

Dye Class Chemical/Macroscopic: Visualassessment of if* solubility and reduction reactions

Specific Dye Chemical/Macroscopic: Visual assessment of thin layer chromatograms

Chemical/Microscopic: Infrared spectroscopy; visible absorption spectrophotometry

Specific Mordant Chemical/Macroscopic: Visual assessment of ashing

Chemical/Microscopic: X-rayfluorescence; X-ray oilcroprobe

Table 4 Dye and mordant properties

40

1.3.

5.8.U.12.

15.17.

18.19.

2.4.6.9.

13.

16.20.

7.1Q.14.

Stratum

Blue Samples

Wool, Abu Seiffein, 1981Wool, Monastery of Martyrs, 1981

Silk, Abu Seiffein, 1978Silk, Abu Seiffein, 1981Cotton, Abu Seiffein, 1978Cotton, Abu Seiffein, 1981

Cotton, Monastery of Martyrs, 1981Flax, Abu Seiffein, 1978

Flax, Abu Seiffein, 1981Flax, Monastery of Martyrs, 1981

Red Samples

Wool, Abu Seiffein;,, 19.8 LWool, Monastery of Martyrs. 1981Silk, Abu Seiffein, 1978Silk, Abu Seiffein, 1981

Cotton, Abu Seiffein, 1981

Cotton, Monastery of Martyrs, 1981Flax, Monastery of Martyrs, 1981

Yellow Samples

Silk, Abu S*iffein, 1978Silk, Abu Seiffein, 1981Cotton, Abu Seiffein, 1981

Locus

I. surfaceII. x. surface. NWA1II.x. surface.. SWA2II. x. surface1.2.3*1.2.941.2.25I. surf aceI. surface1.2.741.2.106II. xiv. surface1.2.321.2.261.2.111

II. x. surface. SWA1

I. surfaceII. x. surface. NEBl1.2.35I. surface1.2.106I. surface1.2.1071.2.109II. x. surface. NEA1II. x. surface. NEB1

1.2:^.1I . 2. 106I. surface

TextileNumber

842222251375

139B151

73102172106028

243221236;

302208358A18570

198199229A231

80SffS

4

Table 5Blue, red and yellow dyed samples analyzed

to determine dye application classy dye and mordant

41