I want to do an activity with 2nd graders using natural dyes, and I've researched a little on the Internet, but I'd like to get some suggestions from hands-on people.

I'd like to prepare the dyes at home and use them at school. Will this work?

I've read of fixatives (mordants?), but I don't think I need these since we won't be washing our work. Right?

I also have concerns about toxicity of certain plants I might use. I would only want to use the safest plants.

Thanks for any help.