Most puzzles marketed to adults have 300 to 750 pieces, but some of the most sophisticated have as many as 5,000. Costco was even selling a 29-foot, 60,000-piece puzzle.

Let’s say you have 40 pieces of blue sky in the corner of a jigsaw puzzle and need a quick way to determine how the pieces lay. At this point, Jill recommends looking at the paper formation.

Each puzzle piece must be uniquely shaped, to avoid one accidentally fitting into the wrong place. That means 1,000 different shapes for a 1,000-piece puzzle, each drawn by hand by workers.