Modern puzzles are mostly made of cardboard, which makes them cheaper and easier to make. The pattern of a indoor puzzle is a whole piece of fine art printed on the surface of cardboard before cutting. The content of the picture can be enlarged photography, painting, or other kinds of flat art. The mapped cardboard will be sent to a special stamping machine, which is equipped with a steel cutting tool set in a predetermined pattern. After being pressed by the machine, the cardboard will be cut into pieces by the cutting tool set. The process is similar to that of a graphic cookie, except that the jigsaw presses have a much higher impact. For a typical 1,000-piece indoor puzzle, for example, up to 700 tons of pressure are required to be generated during the operation of the machine tool in order for the tool bank on the die to fully cut through the cardboard. The die (printing plate) of the indoor puzzle is usually made of plywood and other plates. The mold maker first marks or burns grooves on the template according to the pattern of indoor pieces, and then inserts the one by one into the grooves to assemble the tool set. The tool set is also covered with a layer of elastic material, usually foam rubber, which is used to cardboard pieces out of the holes in the tool set after printing.