Immerse the sealed bag in a bowl filled with warm water (30 to 40°C). Remove the dough from the bag and knead for 5 to 10 minutes, adding a few drops of water if needed.

In the windowless frame, press the dough and spread it with your fingers or the back of a spoon. Lather your hands to remove any dough residue.

Place the child's foot or hand (or a dog's or cat's paw) on the dough. To mark the entire print, press the fingers for 20 seconds and the palm for 20 seconds.

Wash the hand or foot carefully to remove all dough residue. Allow to dry for 2 to 3 days (the dough will shrink slightly). Paint the frame with acrylic paint.