Iceblossom

I have used Rit Dye on sheets before, mostly while experimenting with patterns and techniques. I really prefer the heat set/microwave method above all others, and follow their directions for setting the colors. Haven't done it for awhile but I think they do recommend either pre- or post-treating.

My reds tended to fade quite a bit as well as bleed, blue/green/purple seemed to hold up well.

On a somewhat unrelated tangent, I found our large local Walmart craft section (next to the fabric if your store still has it) had a lot of good dying supplies along with Tie-Dye kits.

Edit/PS/I forgot to mention -- it is getting harder to find all cotton sheets in thrift stores or whatever any more. Fabric content really makes a difference in dyes, I think the current trend is using rayon for better colors??