I wash before I am going to cut it out. I have a huge stash and do not wash anything until I have picked out the fabric and am ready to cut. I have some of the best fabric possible and it has bled and bled in my kitchen sink. I even washed a quilt top I bought at a yard sale and it bled the red onto the white and I did use a color catcher in the washer with it. I use color catchers all the time but I would never make a quilt without washing the fabric first. Yellow, green, red and purple always bleed the most for me. My last quilt cost me $200 to make and I used Joann's fabric and everything I bought was on sale, still a lot of money to waste if the colors ran and ruined it.