Is there a faster way to count jigsaw puzzle pieces?

Question

I have a number of old 1000-piece jigsaw puzzles I'd like to sell. I'd like to make sure they are complete first. Is there a faster way to determine whether there are exactly 1000 jigsaw pieces than physically picking up and counting every single one of them?

Answer 1

I don't know of one. To know the number you should have (it may not be exactly 1000), you can assemble the border. Many puzzles are cut with a rectangular grid and you can multiply the number of rows by the number of columns. Unfortunately, I have also seen a number where the grid is perturbed in a small region of the center and the count is changed by 1 or 2.

With an accurate scale, if you have more than one puzzle in the same series, you could weigh the pieces. The thickness and outer dimensions will be nominally the same. Whether they are controlled within 0.1%, however, may be questionable.

Answer 2

I once tried once piece on a digital scale, then weighing the lot, however I did not find this to be a very accurate way of determining a amount of puzzle pieces.

Answer 3

Note: While the thread may have long served it's purpose, I am proposing the following for archival purpose.

You can take a photo after scattering them on a white background and use any software that uses thermal imaging to count, or use infrared beam by having them slide in a narrow strip at an angle that will interfere with the light registering a 'tick'.