Although I haven't tried, I've read that the only yarn that is properly dyable is animal fibers. I'm not sure if you have to do something special to the cotton to get it to hold or what. I mean, you can dye a t-shirt with that Rit dye, so surely there is something you can do, right? :thinking:
It was only a dishcloth so I thought I would just try to wilton dye it anyway. It did not turn out. The dye just would not stick, it was blue and when I threw it into the washing machine it turned pink. Maybe the rit dye would work better.