Will excess dye bleed onto an undyed portion of the fabric? Will it bleed onto a section of silk that I’ve already dyed a different color?
To vat-dye multi-colored silks with clean colors and smooth transitions, there are a few different methods that work. This particular method is one of the easiest, since it blocks off all of the fabric that you’re not currently dyeing, allowing you to vat dye and machine wash as usual.
To dye multi-colored play silks for my girls, I begin by banding off different sections of the play silk according to where I’ll want the different colors. So far, this method looks exactly like tie-dyeing cotton, and you can use either rubber bands recycled from the daily newspaper, or twine from your stash.
After I’ve banded off the fabric, however, I put all the sections of the fabric that I’m not going to dye at that moment into a watertight plastic baggie, and I often double-bag it just to be safe. Recycled plastic grocery bags could work for this, as well as rinsed and re-used plastic sandwich bags.
Tightly rubber band or tie the bags closed around the fabric, leaving out just the one section that you’re going to dye right at that moment.