I don't know who developed these. I was probably someone like that man who developed the "post-it note" who was trying to accomplish something else and accidently invented post-it notes. I don't care. But those color catchers sure make life easier! If they're really saturated, I will re-wash, just to make sure I don't have a bleeding problem. If I didn't have them, I wouldn't know if they were bleeding unless I did the old fashioned "bleeding test" (which actually I sometimes still do." And if I don't stop, I'm going to sound like a commercial, but I do like the Shout one!
Merry Christmas!