I wasn't sure what forum to put this in, because this is for a project where I want to take large cardboard boxes, and either cover them with contact paper or somehow paint them so that they are colorful lightweight giant blocks. I didn't post in the toy forum because questions about contact paper seem more of a 'mindful home' issue.
Anyways, I think contact paper is made out of vinyl, which I wouldn't want to be something my daughter handled a lot when playing. Is there a green alternative that will work as well as contact paper?
I'm not sure how old your daughter is, but how about having her decorate them with crayons, markers, paint, etc. They won't look as nice as if you do it but she will have fun decorating them and then playing with them. Every time we have a box my children want to decorate it or turn it into something.
Paint them. You can have her color on them next, but crayons and markers don't show up well on boxes, and even if she paints she may be frustrated by continuing to see the logos and such on the boxes.
Paper is a nuisance to glue on and can tear readily.