Depends on their skills. I too a panel already printed and painted it with them. I ironed the fabric to the shinny part of freezer paper to stabilize it. I am not sure I would recommend it for 7 years old. They don't work like crayons. I have seen most people use them to paint with stencils. For that you will need sponges or short brushed. If you want to paint with brushes, what I do is to of course, peel the protective skin and paint a chuck on freezer paper. Then use a very short brush to pick it up and spread it on the fabric. I believe they are too expensive just to see if the kids will be able to paint with them. They are indeed long lasting if you let it dry for at least 5 days and then fix it with the iron.
This is the link to the quilt I made with them:
http://www.artfire.com/modules.php?n...uct_id=2176957