By its nature batik will run some and over time fade. No need to wash it as it has been washed probably once for each color in it. Due to the dyes used it is hard for a needle to pierce sometimes. We quilters use it alot and enjoy it but we know it has faults.

True Batiks like Hoffman and Pacific Rim are wonderful to sew on. I do run them through a wash and dry , as I do all my fabrics, to make sure that any excess dye clears. I have made many quilts with batik fabrics. They don't fade as fast as some other commercially dyed fabrics. Sun is fabrics worst enemy. One of my goals in life is to visit Bali and the factorys where they are made.

See that you've gotten excellent answers. You can use either the rayon or poly threads which ever you prefer.