To make scratch off solution, mix 2 parts metallic acrylic paint with 1 part dishwashing liquid. Using a small, flat brush apply a thin coat of the solution onto the front side of contact paper and let dry for an hour. Repeat with a second coat, and add a third coat if your paint looks streaky. Cut out the hearts, peel off the backing and place over the heart spaces on the card. Package with a new penny.