3.1 Fleece processing
The end product of a woven fabric is determined from the start of the production process by selecting the proper fibres from a fleece. Analysis of the fibres in archaeological textiles provides information about the natural colour, type and fineness of the wool selected for specific types of textiles. The earlier fleece type analyses were conducted using a chronological model of fleece evolution from hairy to fine and evenly distributed fleeces (Ryder 1964). Modern critics have argued that this approach is not useful for archaeological textiles. Ryder’s model does not take into account that the fleece from one single sheep varies greatly depending on which part of the body it came from. It also assumes that wool was used straight from a sheep when it is more likely that it was prepared, sorted and selected to create a better yarn (Christiansen 2004, Rast-Eicher 2008). Fleece analysis will therefore not provide chronological information but may provide evidence for the preparation of the fibre before it was spun into threads.
Recently the fleece type of several Dutch samples was analysed in order to compare these textiles to those from northern Germany (Walton Rogers 1995), Norway and Denmark (Bender Jørgensen & Walton 1986; Walton 1988) and Anglo-Saxon England (Walton Rogers 2007, 10-14, 62-64). Twenty-eight samples of Early Medieval textiles were selected for a quick scan of animal coat and natural pigmentation (table 3; analysis by P. Walton Rogers, the Anglo-Saxon Laboratory). All except two textiles proved to be made from sheep’s wool. A textile from Beetgum was almost certainly made from the undercoat of goat. Only four textiles were made from white fleeces. Among these were unusual fabric types, not necessarily locally produced (a felt from Ferwerd and a gauze-like textile, or Schleiergewebe, from Leens). The hat found at Oostrum (fig. 3) was also made from naturally white wool. Dark brown or black was the most common colour for twills and diamond twills.
Table 3. Textiles analyzed for fibre and natural pigmentation. mod. = moderate; stch = stitching. (Analysis by P. Walton Rogers, The Anglo-Saxon Laboratory).
Several fabrics were woven in a colour pattern using threads of different colours and thus creating stripes or blocks within the fabric. Macroscopically, this technique has only been observed in five textiles, but based on results of microscopic analysis, we may assume that it was applied more frequently. Fibre analyses show that six out of 28 textiles (21%) were woven with naturally dark wool in one thread system and originally light wool in the other thread-system. Among these were four textiles that had not been macroscopically recognised as such.
Seventeen samples from seven different textiles were selected for further analysis of fleece type (table 4). Warp, weft and any sewing thread or pile yarns were analysed separately. In order to identify the fleece type, 100 fibres were measured and the results plotted as a histogram.
Fig. 3 Hat found in Oostrum (object nr. FM 35B-48). The hat was made from naturally white wool which was dyed a light red. The decorative stitching was made in a darker red yarn (collection Fries Museum).
According to the range, mode, mean and degree of skew of the measurements, the samples were allocated to one of seven fleece-type categories: Hairy (H), Hairy Medium (HM), Medium (M), Generalised Medium (GM), Fine (F), Semi-Fine (SF; previously called Shortwool) and Fine/Generalised Medium (F/GM). Eleven of the samples were HM, one was GM, two M and three samples (all from the same textile, Beetgum lab.nos. 46-95) were goat fibre.
Only two textiles show evidence for the special preparation of wool. The white wools in warp and weft of the gauze-like tabby, or Schleiergewebe  have been allocated to the M category because of their symmetrical spread of the fibre diameters and their means between 30 and 40 microns, although the maximum diameter for the M type should be 60 microns and both yarns include a single fibre thicker than 60 microns in diameter (table 3). The wools in a similar textile from Hessens, Stadt Wilhelmshaven, in north Germany (He33a, and possibly also in He31c), were similarly difficult to categorise and it was suggested that they may represent an HM fleece from which the hairs had been stripped out. The same may be true of the Leens example (Walton Rogers, unpublished). These textiles are also found in Anglo-Saxon England and in Viking Age Denmark, Britain and Ireland, and it is possible that they represent trade goods produced in a specialist workshop (Walton Rogers 2007, 68-69).
The textile from Beetgum is made from goat fibres. The outer coat hairs are absent in this case, which may indicate that the underwool was combed directly from the animal during its spring moult.
The Dutch textiles resemble those from northern Germany. Previous research on 27 samples from mainly seventh to ninth century sites in northern Germany shows that the textiles were made from fleeces that are categorized as Hairy or Hairy Medium. Similar results were obtained from samples of raw wool found at the same settlements. This may indicate that the wool was processed in the settlement, making the woven textiles a local product. Many fibres were originally of a brown or mottled brown colour. White fleeces were only observed in 22% of the threads. In contrast to the Dutch textiles, all textiles were woven with wool which was originally the same colour in both warp and weft (Walton Rogers 1995, table 3). Some of the same fabrics and pigmented fleece types are also found in Anglo-Saxon England, although the English material has a larger share of white wool and a wider range of fleeces. The terpen evidence contrasts with the material from Norway, which shows a much more precise method of selecting and processing wool.
The raw materials from the textiles from the terpen, found in the north German and Dutch settlements show a wider range of fleece types and a lack of carefully sorting which makes them closer in type to the Hessens-Elisenhof type textiles excavated in southern Scandinavia (Walton 1988, 153; Bender Jørgensen 1984, 130-1, Walton Rogers, unpublished).