I would use fabrics that bleeds color in the wash, but I would make a garment or something using only the fabric in question. Washing the piece separately would be a must, lots of slik shirts and blouses are like that. Patchwork would be impossible. Various color fast treatments, rinsing in vinegar, and similar tricks are worth it on a finished piece. I have used color catch a few times, just to make sure dark patches doesn't bleed on the paler ones.