These puzzles are made from single sheets of felt like material with a pattern cut into it like a jigsaw puzzle. The pieces, however, are not cut 100% so they stay attached in a single strand. In this way you can never lose a piece. The puzzle has a picture on both side - like having two puzzles in one. They are perfect for traveling or while waiting (doctor's office, dentist, anywhere you end up sitting with nothing to do). Take a look at this utube video for a close up look at the pieceless puzzle.