I remember when puzzles use to be flat and after the puzzle was put together it was either put back in the box or put out in the next garage sale. Esphera has brought in a new era with not just a fun puzzle to play with but a very nice decoration to anyones home. This puzzle is incredible. It is made of hard plastic and forms a ball with the pieces ever so slightly curved. Two ways of putting the ball together 1) novice using numbers 2) advanced using the picture.