Scratching off lottery tickets can be fun every once in a while, and Instructables user hellobrit shows in the video above that it's simple to bring a scratch off message to your valentine this year.
Making scratch-off paint is easy; just mix two-parts acrylic paint to one-part dish soap. Go ahead and print out the card or get the Polaroid photo you want to cover ready. Tape off portions of the card or use a stencil to make sure your scratch-off paint is only applied where you want. Let the paint dry and you'll probably need to add a second coat to completely cover your message or photo.
This method makes for a cute valentine -- if you need a creative way to say 'I Love You' consider giving it a try.
Scratch-Off Photo Valentine [Instructables]