I wash all my fabric. My decision came after seeing a black fabric bleed a lovely shade of purple and destroyed a quilt my friend made. She was sick and so was I. But, if you ever look at the water you wash your fabric in, you'll notice it is filthy. This stuff gets handled and stored in warehouses, shipped in containers on pallets maybe wrapped, maybe not. Dirt, bugs, rodents, yuck! Staph hangs around a long time on surfaces. I am not willing to take the chance. Hygiene aside, a little caution can save us from a lot of heartache and pain.