I always pretreat batiks with Retayne. Retayne will set the dye as batiks always bleed. Use 1 tsp of Retayne for every yard of fabric. Soak in hot water for 20 minutes. Rinse and dry. The instructions are on the bottle.
I love working with batiks.
Judy
http://www.prochemical.com/directions/Retayne.htm