I have never used a bleach pen and am wondering if this could be a fun/safe project for kids. I was thinking of using colored t-shirts and having kids "draw" with the bleach pen. What do you think?

Sam, As long as the kids are supervised and over the age where they might put the pen in their mouths I'd go for it!

i tried this on a denim scrap once, with the idea that i could really funk up a jacket. it looks good from a distance, but not so much up close. the edges were really irregular (not in a charming way). but different fabrics probably will take the bleach different ways, so it's definitely worth experimenting!