Okay, so it's not exactly junk mail, it's newspaper inserts.
Cut a whole bunch of strips from colorful ads or magazines. I looked for pink and red and orange for mine.
Weave the strips together, over-under-over-under, just like you did in kindergarten. (I laid all my horizontal pieces out first and taped one side down to the table to keep them from slipping around, then wove the verticals in.)
Make a heart cut-out from scrap paper to fit the weaving you have made. Lay it on your weaving to check the size and shape.
When you are satisfied, tape all the way around the weaving to hold the strips together and use your scrap paper heart as a template to trace the heart onto the back side of card stock. Cut out the heart from your card stock.
Spread glue around the heart opening, on the wrong side of the card stock.
Place the heart cutout on top of the weaving, gluing them together. Put a book on it and let it dry.
Trim the weaving on the back side of the heart. You will want to cover this another piece of paper!
Extreme Cards and Papercrafting: pop up cards, movable and mechanical cards, digital crafts and unusual papercrafts.