The edge pieces are a staple of the standard quadrilateral jigsaw. No matter how big or difficult a jigsaw may be, it will always have pieces that interlock on just three sides. This gives the puzzler a good starting point. But of course, there are those who may not want this advantage and would prefer the challenge of having to put real effort in to get started.

These jigsaws would have intermittent edge pieces designed to fit in the middle of the puzzle. It sounds crazy, I know, but please bear with me. These pieces would come in pairs with the flat edge of each matching up. Adding a limited number of these would make figuring out what is or isn't an actual edge piece that much more difficult, thus adding to the challenge, leaving you with one happy jigsawlogist.
-- hidden truths, Jul 19 2006

FarmerJohn's Wraparound Approach Endless_20Puzzle
Cylindrical, so it still has top and bottom edges. [DrCurry, Jul 19 2006]

Edgeless Jigsaw Puzzle http://www.unclesga...01c12f1588ac4936a85
...with five extra pieces. One of a series. [DrCurry, Jul 19 2006]

Wiki has a good article on the subject http://en.wikipedia.../wiki/Jigsaw_puzzle
[DrCurry, Jul 19 2006]

The Worlds Hardest Jigsaw http://www.britsupe..._Cornflakes_1kg.jpg
It's All Beak?!?! [MikeOliver, Jul 19 2006]

here are other than square jigsaw puzzles http://www.bitsandp...23&page=2&viewAll=1
Uses your idea in reverse, no flat edges.. [xandram, Jul 19 2006]

Waddington's Jig-map http://www.puzzlehistory.com/jigmap.htm
I loved these when I was little - not a straight line in sight. [wagster, Jul 20 2006]

Noice.
-- calum, Jul 19 2006


does the edge have to be straight anyway.

what calum said.
-- po, Jul 19 2006


Not necessarily but I think it makes it look more complete [po].
-- hidden truths, Jul 19 2006


Or non euclidian ones? Or spherical ones - like a global jigsaw of the world (though you would still be able to sort the pieces into general sea and not-sea piles - and, based on the presence of polar bears/penguins, arctic and antarctic ones too)
-- zen_tom, Jul 19 2006


....and then you use a Jackson Pollock painting as your subject matter, and, and, and, and, if it was a farmyard scene instead, would it be a Pigsaw?

It's best to get all these off your chest in one go.

Croissant for the jigsaw maker +
-- xenzag, Jul 19 2006


it would still be relatively easy, after having sifted out the edge pieces, to match up the pairs that belong somehwere in the middle.

How about making *all* the edges straight? (Of course, it wouldn't be a jigsaw puzzle at that point, but some kind of tile puzzle.)

Another approach to this problem, producing edgeless (i.e., wraparound) jigsaw puzzles, is Baked, although I can't immediately find a link for you.
-- DrCurry, Jul 19 2006


Alternatively, take a regular Jigsaw, pick out all the edge pieces, and throw them away.
Now the second edge level becomes the edge, and the difficulty increases.

-- MikeOliver, Jul 19 2006


The interior edges could help emphasize lines within the picture. In fact, the two meeting edges need not be the same color.
-- phundug, Jul 19 2006


Or make all of the pieces triangles. Or circles!
-- bungston, Jul 19 2006


Interlock on 2 sides only and all pieces resemble corners.
-- Shz, Jul 20 2006



random, halfbakery