A few things I've learned:
Don't use the cheap drugstore dyes (like Rit or similar) because they will fade and will leak to other things. I tried this on just ONE rag, and after four times through the was on its own it stained a bunch of ivory-white bath-towels into a peachy/light-pink color. Not cool.
Use a LOT of dye. If you are folding in some way that makes a lot of fabric not visible, make certain that the dye is reaching the insides. I've got a couple of dipes that came out as splotches of color.
The Rainbow Rock dyes work well
. I like those. It takes quite a good deal of dye to create bright colors on a prefold, though, because they can really soak things up. The Gerber ones are a different story, though - you can easily do 2 dozen with one box of Rainbow Rock dyes.
Don't use the cheap drugstore dyes (like Rit or similar) because they will fade and will leak to other things. I tried this on just ONE rag, and after four times through the was on its own it stained a bunch of ivory-white bath-towels into a peachy/light-pink color. Not cool.
Use a LOT of dye. If you are folding in some way that makes a lot of fabric not visible, make certain that the dye is reaching the insides. I've got a couple of dipes that came out as splotches of color.
The Rainbow Rock dyes work well