If you're already inundated with Valentine crafts and are trying not to scream at the very thought of another, you may skip this article. If, however, you're looking for a fun craft to do with your kids, with items you probably already have in the house, read on!
I have done this craft with children from age 2 to 22 years. Because an iron is used, adult supervision is always required -- unless your children, like mine, are currently ironing their own clothes!
Gather your materials:
old crayons (in Valentine colors. We used red, pink -- and yellow. Paler colors let more light through.)
a grater
wax paper, cut into squares the size of the hearts you choose. Mine were about 7 inches square. (Or thereabouts. This is craft, not science!)
newspaper
red or pink construction paper
an iron
1.) Grate your crayons into separate piles of colour. (The shavings will be full of static charge, and will stick to everything. It helps to have slightly damp hands when you try to move them.) 
2.) Use a couple of sections of the newspaper to make a pad on your table. Place a sheet of wax paper on the paper. Sprinkle crayon shavings onto the wax paper. (Less is more: too much, and the light won't shine through.)
3.) Cover the crayon shavings with a second section of wax paper. Top with a sheet or two of newspaper.
4.) Press with iron set on low. (A child as young as three or so can help hold the iron. Older children can do this independently -- with a careful parent nearby!) If you simply hold the iron in various spots, the crayons will melt in place. If you move the iron, the colors will swirl and meld a bit. Totally up to you!
8.) String a ribbon through the frame, and ta-dah! A Valentine sun-catcher to brighten a dreary February afternoon!
