Although Terry Mattison is the first to say that she's still exploring and learning about natural dyes, she has achieved great results (and great adventures) connecting the realm of fiber with the kingdoms of plant and fungus.
Mushroom Dyeing
You might be surprised to learn that mushrooms can yield a huge range of colors, even some that can be challenging with plant dyes. Here are a few of Terry's results.
https://images.ctfassets.net/cjwcissb5f6t/2fewEQBbbiVIFqC6vmbC6E/49d9728c191c6aa1c85642c2ce7f5a77/Mushroom-dyed-fiber.jpg?w=500&fm=webp
https://images.ctfassets.net/cjwcissb5f6t/3ZlYHBZuy213j4ve64Ttog/d904466e3a77f9c97536127eb7c98c1f/Natural-dyes.jpg?w=500&fm=webp
Terry's sample kit for testing for colors in mushrooms fits in a small lunchbox.
https://images.ctfassets.net/cjwcissb5f6t/3ukMzZBYXjBlvzL0QJWyn7/c126306be704f0469ad0418d9a402703/Mushroom-Kit.jpg?w=500&fm=webp
To learn more about mushroom dyeing, check out Alissa Allen and Mycopigments (https://www.mycopigments.com/). The Facebook group Mushroom and Lichen Dyers United (https://www.facebook.com/groups/mycopigments/) offers resources and discussions from other dyers.
Botanical Printing
Combining the chemistry of plant dyeing with the line and form of printing, botanical printing (also known as eco-printing) can create spectacular results. Below, a printed napkin that Terry disliked the color of, transformed with a wash of iron.
https://images.ctfassets.net/cjwcissb5f6t/7Jn0F18wmUHexYhobkjewA/31b10793aeb7f21e7aa60617a69c3cf4/Printed-napkins.jpg?w=800&fm=webp
https://images.ctfassets.net/cjwcissb5f6t/dMsMVYLnG9opHcQUmfp0J/078584c3d818593d0e77c962fb770523/Leaf-print.jpg?w=800&fm=webp
To learn more about botanical printing, check out The Best of Both Worlds: Enhanced Botanical Printing (https://janedunnewold.com/books-and-digital-media/the-best-of-both-worlds-enhanced-botanical-printing-preorder) by Jane Dunnewold or Bundle, Steam, Print! (https://www.eugenetextilecenter.com/bundle-steam-print) by Janis Thompson.
Natural Dyes
Maiwa (https://maiwa.com/) has recently made their extraordinary knowledge base of natural dyeing available online at their Natural Dyes website (https://naturaldyes.ca/).
Some natural dyers strongly prefer color that is fast, i.e. unchanged by washing, light, and time; others allowing or even prefer changeable colors, which are known as "fugitive."