A jigsaw puzzle is a tiling puzzle that requires the assembly of often oddly shaped interlocking and tessellating pieces.
Each piece usually has a small part of a picture on it; when complete, a jigsaw puzzle produces a complete picture. In some cases more advanced types have appeared on the market, such as spherical jigsaws and puzzles showing optical illusions.
Jigsaw puzzles were originally created by painting a picture on a flat, rectangular piece of wood, and then cutting that picture into small pieces with a jigsaw, hence the name. John Spilsbury, a London cartographer and engraver, is credited with commercializing jigsaw puzzles around 1760. Jigsaw puzzles have since come to be made primarily of cardboard.
Typical images found on jigsaw puzzles include scenes from nature, buildings, and repetitive designs. Castles and mountains are two traditional subjects. However, any kind of picture can be used to make a jigsaw puzzle; some companies offer to turn personal photographs into puzzles. Completed puzzles can also be attached to a backing with adhesive to be used as artwork.