I wash, always. Every time I have not washed, something has bled badly. Once a red applique rose bled into the white background of a piece I'd spent many many hours hand appliqueing. Thank god it washed out with several rinse and a handful of color catchers. Never again. Everything goes right from the shop bag into the laundry hamper, and if I am afraid it might still bleed (had one red that bled after several washings) it gets tested with white fabric.