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Chilkat Dye Research

Blue/Green Materials

Sources of Blue and Green Dyes

Natural blue dyes are rare. Most of the blues our chemist collaborators have analyzed from the robes in our collection are synthetic. Historical and oral sources suggest indigo, copper, or “blue clay” made blue and green dyes, too.


Indigo could have been a trade item or boiled from trade cloth in a vat of urine. We failed to boil indigo from yarn using urine, but succeeded using equivalent laboratory chemicals. The resulting dyebath made a pale blue. We also experimented with overdyeing natural yellows with indigo to give various greens.

Copper and Ammonia

A piece of copper pipe in a jar of ammonia will give a vibrant cobalt-blue solution and vividly-colored corrosion products on the copper. But these colors are not the final dye colors. Yarn dipped in copper/ammonia solution turns a dull gray-green. Subsequent dipping into vinegar immediately gives a pleasing minty-green color.

Blue Clay

The “blue clay” remains a mystery. We wondered if it might be vivianite, a blue clay used to make a paint pigment. After much failed experimentation, it seems unlikely. In general, minerals that make good pigments for paints do not make good dyes because their particle size is too large and cannot be bonded easily to the fiber.

Mushrooms and Lichens

Some mushrooms and lichens are said to yield blue dyes. Lepraria lichen may have been used on vest SJ-I-A-48. While there are no historical accounts of mushrooms or lichens used for blue/green dyes, weavers have always been open to innovations in dyeing and continue to explore natural options from the land.

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Case Contents

From the exhibition The Spirit Wraps Around You (May 8–October 9, 2021 at the Alaska State Museum):

  1. Jar of commercial indigo powder. None of the analysis of historic Chilkat robes done by our colleagues at Portland State University has shown indigo. But it has been mentioned in historical texts, so we have been researching the indigo option.
  2. Jar of indigo solution
  3. Jar of thiourea dioxide and soda ash used to extract indigo from dyed yarn and put it back into the dyebath. This experiment by conservation intern Steph Guidera (of the SUNY Buffalo State College Conservation Program) mimics the chemistry of historic accounts of removing indigo from trade blankets by boiling in urine. The yarn now looks white and the liquid colorless. Interestingly, the yarn becomes springy like a rubber band and then very brittle when dry. Our attempts to remove indigo from yarn by boiling in aged urine did not work, but the difficulty of working with indigo and urine is well known to master dyers and it is likely simply lack of skill.
  4. Yarn (pale blue) dipped once in the indigo-extracted dyebath
  5. Yarn “Indigo 1st dip 1st batch July 27, 2020 ASM Steph Guidera” from commercial indigo
  6. Yarn “Indigo re-dipped 3X” from commercial indigo
  7. Yarn “Indigo by Katherine Kinney (SUNY Buffalo State College Conservation Program)”
  8. Yarn “Horsetail alkaline pH simmer, baking soda, steep overnight, dip 30 sec (in indigo) then dry, then 2nd dip in indigo)”
  9. Yarn “Lupine flower, neutral pH, indigo (overdye)”
  10. Yarn “Yarrow blossom (white) neutral pH, indigo (overdye)”
  11. Yarn Goat’s beard flower, neutral pH, overdyed indigo, dip 30sec, dried, 2nd dip”
  12. Yarn “cow parsnip, urine, merino wool, no scour”
  13. Yarn “alder bark, overdyed indigo, 2 dips of 30 secs” These examples of color from overdying indigo with our natural colors did not seem to give colors that Chilkat weavers typically use.
  14. Copper pipe with various corrosion products and deposits from soaking in ammonia
  15. Jar of copper/ammonia solution dyebath. Note the yarns do not come out with the colors seen on the pipe nor in the liquid dyebath.
  16. Yarn “heated copper/ ammonia” from Sophie Lager, in natural dye class taught by Lily Hope.
  17. Yarn “copper + ammonia, Merino wool, no scour, vinegar dip” Dorica Jackson advised that a dip in aged apple cider vinegar turns the dull gray-green to a more pleasing minty green. One weaver suffered loss of her jar of aging apple cider vinegar when her spouse located it and used it for adobo.
  18. Yarn “copper/ ammonia” from Sophie Lager, in natural dye class taught by Lily Hope.
  19. Yarn “copper + ammonia, Merino wool, no scour”
  20. Xanthoria lichen sample on rock from Nancy Ratner.
  21. Jar of Xanthoria lichen dyebath
  22. Wool dyed with Xanthoria lichen, pink as dyed then gradually is supposed to turn more blue with light exposure.
  23. Jar with sample of fungus that might dye something blue? Not yet tested, but seen on stumps and other old wood in our local rainforest. Some material that looks like this is called “blue stain fungus” and this casual name has us intrigued.
  24. Three commercial yarn samples given to us by Kay Field Parker. The top one is commercial yarn from “Spin Right,” a mill popular with weavers before they started buying yarn from Louet. The bottom two are Louet yarns. The center sample was supplied as a Louet color called “Angelfish” and the other two samples started as white yarn and were colored with commercial dyes by Elena and Martin Mountford. 
  25. Jar of chocolate lily dyebath.
  26. Yarn: “Northern rice root (chocolate lily) flower, alkaline pH (baking soda dip)” Written sources suggest this plant can give a blue or green color, and we hope to experiment more with this in 2021.
  27. Jar of crowberries in ethanol for preservation on display. Blueberries and crowberries are known to give blue dyes for a variety of artistic media throughout Alaska including basketry and gut, but the colorfastness is not great.
  28. Yarn: “Crowberry in tap water”
  29. Jar of vivianite clay from ASM collection, II-A-176. This sample was collected by Lt. George Thornton Emmons in Western Alaska, but there are said to be sources in Southeast Alaska in the Wrangell area. References suggest “blue clay” was used to make blue-green dye, and we had hoped it might be vivianite because it is a known blue-green pigment for paint on masks and other wood carvings. However, extensive testing by New York University conservation graduate student Adrienne Gendron in summer 2020 failed to bond the colorant to the wool fiber. It is unlikely vivianite was ever a dye even though it was a popular paint  pigment in Alaska. Our “blue clay” mystery continues, and we are now actively looking for examples of tidal clay that may be colored by algae.
  30. Yarn “1-hr dock (broad leaved) stem and seed heads, alum and CoT (cream of tartar)” from Patty Fiorella.
  31. Yarn “½ hr eyebright leaf and stem, 1 hr cooling, alum and CoT (cream of tartar), vinegar/ soap/ tapwater rinses” from Patty Fiorella.
  32. Yarn “½ hr eyebright leaf and stem 1-hr cooling, alum and CoT (cream of tartar), 15-min plain ammonia, sea salt + tap H20 rinse” from Patty Fiorella.
  33. Yarn “8/2020 ½-hr plantain , alum + CoT, 15-min plain ammonia, se salt + tap water rinse” from Patty Fiorella.
  34. Yarn “Yarn “8/2020 ½-hr plantain , alum + CoT, vinegar + tap water, soak/ rinse” from Patty Fiorella.
  35. Jar of urine. Urine has various chemical properties, acting as a mordant to help hold dye to fibers as well as changing the pH of the solution and the salinity. Urine from babies was preferred for various reasons including its chemical purity.
  36. Box of pH test strips.
  37. Bottle of apple cider vinegar.
  38. Bottle of white vinegar.

All unattributed materials listed come from the Alaska State Museum conservation lab and include the after-hours activities of conservator Ellen Carrlee.