There are a couple of pigment dyes that might work or Procion dyes might fit the bill too. Just as a disclaimer, I have never used pigment dyes nor have I "painted" on wool with Procion dyes. However, I have gleaned some info on my travels throught the world of fabric arts
Anyways, Jacquard pigment dyes are heat set, like with an iron. Depending on how thin or thick you apply the dye, it will leave a feel on the fabric. Dharma has some pigement dyes that are similar but do not need heat or other fixative.
Thickened procion dyes would work well, too. You could stamp, stencil, paint on the design, wrap your soaker in plastic, steam it and rinse. Check out
http://gfwsheep.com/rov.inst/rov.inst.html . This page gives info on hand painting wool roving so that it is varigated but the actual prep and finishing steps wouldn't be too far off for what you want to do. She is also using acid dyes, but you can easily replace them with Procion dyes. Remember, when using procion dyes with wool, you must use an acid like citric acid or acetic acid( or a lot of vinegar) for the reaction to take place between the fibers and the dye.
Anyways...I hope I have sent you in the right direction. Heck, go to Joanns, they might have just what you need
Kathy
