You may know this technique as incire, cut and fold, lacé or cut 'n tuc.
Assembly is simple: cut the pattern, score each crease line, and fold back each little piece along the crease. Each heart outline tucks under the center of the heart next to it. Glue to a backing card and you're done!
Extreme Cards and Papercrafting: pop up cards, movable and mechanical cards, digital crafts and unusual papercrafts.