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 mapmaker and engraver, is credited with commercialising jigsaw puzzles around 1760. Spilsbury mounted one of his maps on a sheet of hardwood and cut around the borders of the countries using a fine-bladed marquetry saw. The end product was an educational pastime, designed as an aid in teaching British children their geography. The idea caught on and, until about 1820, jigsaw puzzles remained primarily educational tools.
In 1880, with the introduction of the treadle saw, what had previously been known as dissections (not a word with particularly enjoyable connotations in our own time) came to be known as jigsaw puzzles, although they were actually cut by a fretsaw, not a true jigsaw. Towards the end of the century plywood came to be used. With illustrations glued or painted on the front of the wood, pencil tracings of where to cut were made on the back. These pencil tracings can still be found on some of these older puzzles.
The Golden Age of jigsaw puzzles came in the 1920s and 1930s with companies like Chad Valley and Victory in Great Britain and Einson-Freeman, Viking and others in the United States producing a wide range of puzzles reflecting both the desire for sentimental scenes, enthusiasm for the new technologies in rail and shipping and, last but not least, new marketing strategies.
One strategy was to make cardboard puzzles more intricate and difficult, thus appealing as much to adults as to children. Another was to use jigsaw puzzles as premiums for advertising purposes. Einson-Freeman of Long Island City, New York began this practice in 1931, making puzzles that were given away with toothbrushes. Other premiums followed, but more important to the jigsaw puzzle's enduring success was the introduction of the weekly puzzle. This practice began in the United States in September, 1932-very much the depth of the Depression-with an initial printing of 12,000 puzzles. Soon after, printings rose to 100,000 and then 200,000.
It might seem odd at first glance that a non-necessity like a jigsaw puzzle would sell so well in the Depression. But the appeal, then as now, was that one bought a good deal of entertainment for a small price. The weekly jigsaw puzzle could constitute a solitary or group activity, and would occupy one's time enjoyably for hours. And, of course, a jigsaw puzzle was 'recyclable,' in that one could break the puzzle up once one had completed it and then pass it on to another family member or friend. Another point to bear in mind that jigsaw puzzle enthusiasts in the Depression discovered what many in our own time are rediscovering-that working on a jigsaw puzzle is a great way to reduce stress!
The popularity of jigsaw puzzles has waxed and waned since the Depression. They are still, just like the first jigsaw puzzle, sometimes used to teach geography: I recall assembling a puzzle of the continental states of the USA when I was a boy. (Texas was an easy piece to locate, Colorado quite challenging.) They are still available in both wood and cardboard. They are still a lot of entertainment for a small price. Jigsaw puzzles are a pastime, and I will make no nobler claim for them. But they are a healthier pastime than watching inane (and occasionally vulgar) television shows or playing inane (and occasionally vulgar and/or violent) computer games. And if they are addictive-and they are- they are a harmless addiction.
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.
During recent years a range of jigsaw puzzle accessories including boards, cases, frames and roll-up mats has become available that are designed to assist jigsaw puzzle enthusiasts.
Jigsaw puzzles typically come in 300-piece, 500-piece, 750-piece, and 1,000-piece sizes, however the largest commercial puzzle has 24,000 pieces and spans 428 cm by 157 cm. The most common layout for a thousand-piece puzzle is 38 pieces by 27 pieces, for a total count of 1,026 pieces. The majority of 500-piece puzzles are 27 pieces by 19 pieces. Children's jigsaw puzzles come in a great variety of sizes, rated by the number of pieces. A few puzzles are made double-sided, so that they can be solved from either side, which adds a level of complexity, because one cannot be certain that one is viewing the correct sides of the pieces.
More info and source: Wikipedia