I have used these Color Catchers many times with good results, with one exception. Once I made Bumblebee costumes out of bright mustard yellow and black fleece for my husband and myself. They were lined and stuffed and looked amazing. I didn't pre-treat the fabric. After we wore them, I removed the polyfil and laundered them using Color Catchers. It ruined the costumes. When I took them out of the washing machine, they were a pale yellow and more of a dull dark brown than a black. I ended up throwing them away, which was a shame as all my materials had costed me about 75 dollars, not to mention the time it took to make them.