Through the use of modern chemical analysis it can be demonstrated that certain plants, chemical coloring agents, and classes of colorants were known and used on textiles from the Viking Age.
Based on chemical analyses of actual wool textiles, the following plants were more or less certainly used to dye wool textiles of the Viking Age.
- Galium boreale (northern bedstraw)
- Isatis tinctoria L. (woad)
- Juglans regia (English walnut)
- Rubia tinctorium L. (madder)
- Xanthoria parietina (common yellow wall-lichen, also called shore lichen)
- at least one lichen that yields purples, possibly from Ochrolechia tartarea
Based on chemical analyses of actual imported silk textiles, the following dyestuffs were more or less certainly used to dye imported silk textiles available in the Viking Age.
- Kermes vermilio (a red Old World bug dye)
- Reseda luteola (weld)
- Rubia tinctorium L. (madder)
- indigotin from woad or indigo
- a lichen purple, possibly from Rocella tinctoris
The following additional plants were most likely used to dye textiles of the Viking Age. Either they sport appropriate chemical proportions of the colorants listed below, or they have been found in Viking Age archaeological contexts suggesting use as dyestuffs.
- Calluna vulgaris L. (heather)
- Diphasium complanatum (also called Lycopodium complanatum, a type of clubmoss probably used as a mordant due to its aluminum content)
- Genista tinctoria L. (broom)
- Reseda luteola L. (weld)
The following unidentified colorants were definitely used to dye textiles of the Viking Age.
And for the chemists among you, the following chemical colorants were definitely used to dye textiles of the Viking Age.
- Alizarin
- Flavone (on silk)
- Indigotin
- Luteolin
- Pseudopurpurin
- Purpurin
The following mordants are fairly certain to have been used to dye textiles of the Viking Age.
- alum
- copper (from bronze dyepots)
- iron
- tannin (possibly from elm bark, Alnus glutinosa)
Colors on Wool
Wool, the chief textile fiber of the Viking Age, was available in white as well as many different natural shades of browns and greys. Such shades could be and often were spun and woven without ever being dyed. Wool dyes very easily, though, and many finds of wool from the Viking Age were dyed in once-bright colors. Sometimes a dyer might use a naturally pigmented wool rather than a white one.
A report on the analysis of 220 samples of Viking Age textiles mentions 90 samples which yielded evidence of dyes. The samples come from
Dublin, Jorvík, and 19 sites in
Norway and
Denmark; the dyes mentioned are red from madder or bedstraw; a purple derived from lichens; our mysterious yellow X [from an unidentified plant]; and a colorant identified as indigotin, almost certainly derived from woad. The insect dye kermes has also been found, and luteolin, presumably from weld, but only on imported silks. (Walton 1988b, 17)
Yellow X is still unknown. Chemical testing has eliminated 25 possible dyestuffs, including weld, broom, buckthorn, heather, chamomile, and saffron (see Walton 1988a for a complete list of dyestuffs tested).
Blended colors are also represented. Indigotin was used in conjunction with other dyes to produce several purples (with madder) and a green (with the unidentified yellow). Madder and lichen used in conjunction yielded a red-violet result (Walton 1988, 18, figure 9). Some evidence of brown from walnut shells has also been found, as well as one or two pieces that were intentionally dyed very dark brownish-black with walnut shells and iron (Hägg 1984, 289).
The chemical evidence of textiles from several different sites seems to point to a preponderance of particular colors appearing in particular areas: reds in the Danelaw, purples in
Ireland, and blues and greens in
Scandinavia proper (Walton 1988, 18). This seeming preference could of course be explained by any number of variables--availability of dyestuffs, the differing site climates, or the sheer vagaries of archaeological discovery. However, although it is carefully hedged, there is a hypothesis in the scientific world that this might possibly reflect regional color preferences rather than archaeochemical factors. It is pleasant to think that this sort of "Viking heraldry" might have been practiced.
Colors on Linens
Linen does not take most historic dyes readily, even when a mordant is used. Accordingly, linen was often bleached or left its natural color (grey if dew-retted, straw if water-retted). Substantive dyes such as woad, however, are fairly successful; accordingly, blue linen may have been more common than we know. There are a few examples of woad- and madder-dyed linens from Birka.
Colors on Silks
Imported silks may have gotten their colors from plants or other materials not available in northwestern
Europe, such as indigo or Tyrian ("royal") purple. No further consideration is given to this issue in this article.