I'm still working with what is in the stash, so my pieces were not the 1/4 yard that Gene suggests. I used blue, pale yellow, and white wool that I jelly rolled, twisted has much as I could, and then brought the ends of the roll together and fastened them so they couldn't unroll. The wool was placed in water with Dawn and heated until the colors bled. White vinegar was added to cause the dye to be reabsorbed. I let the wool simmer for 1 hour after which it went into the washer and dryer.
The results (I think these would make great skies)
Transitional dyeing and marbleizing wool pieces are a lot of fun. The results are a surprise and truly beautiful. I like hooking with the variegated wool as it adds interest to what could be a boring background. The only concern is that I create enough similar wool to complete a project and not run short.