I rainbow dye most of the fibres I use for tapestry yarns. I like the unpredictability of the colours, the way the hues blend and the fact that the colours in a rainbow pot always go well together. I spin singles for tapestry weft. The colour transitions in the yarns often substitute for traditional weaving techniques; judicious placement of multi-coloured wefts can mimic the nuances of hachure, for example. Working with multi-coloured singles can make my tapestries appear more complex than they are and I'm all for using illusion to my advantage.
Rainbow dyeing involves nothing more than filling a dye pot with a small amount of hot water, several glubs of vinegar (or other acid), then stuffing the pot with raw fleece. (You can rainbow dye with any fibres or even yarns, washed or not, but acid dyeing with raw fleece is my preferred method.) You then sprinkle acid dye powders in several places on the fleece, heat the pot to a simmer and walk away. There's no stirring, no mixing of dye powders, no more than a bit of judicious poking if the powders don't dissolve. Once the fibres and dyes have simmered for approximately 20 minutes (which varies according to the dyes you use), you turn off the heat and allow the pot to cool over night. You then rinse or scour the wool and allow it to dry. I prefer to wash this Romney without a cleaning agent as I prefer the feel of the grease in the wool. That grease is removed when the yarn is washed and set, so it doesn't affect the woven fabric.
Once the fibre is cleaned, I separate it into batches of locks and fibres to be carded, then into colour groups. Here's the current batch ready to be sorted:
Here are the locks sorted into colour groups:
What doesn't sort into locks will be spun as is for textured yarns or carded and spun into colour blends:
Of course, I would not be as successful at all of this were it not for the faithful Morris, who watches over all events in our backyard. (Really, he's hoping we'll turn on the sprinkler so that he can play in it, He's broken so many sprinkler heads that Mr. DD designed one specially for Morris, built from a hockey puck and a piece of plastic plumbing tubing. At least now, when Morrie bites at the sprinkler, he won't hurt his teeth.The old boy turned nine at the beginning of the month, but you'd never know it when he's romping around in the water.)