One thing I always tell folks who ask me about what books I’d recommend is keep your own book. While its great to have a resource, your own experience will be the greatest teacher when it comes to natural dyeing.
I keep a notebook where I write down every recipe for every dye bath I make, what time of day I pick the ingredients, how long I simmer or soak the yarn or materials, any little detail I can think of. I also keep a small sample of each dye bath, along with information on what kind of wool it is and how much wool got put in.
By keeping notes and samples, we’re able to build knowledge on how the dyes hold up over time, how the heat effects the take up of color, what specific mordants do to the color, ect. And since we’ve done the work ourselves, in our own enviroment with our own tools, we can easily try to recreate certain colors because we know what the factors where for those dyebaths we’re trying to recreate.
While note keeping and documenting doesnt change the fact natural dyeing is fickle by nature and you might never get the same color twice, it helps build confidence and knowlegde much better than a book of recipes from another dyer would.