IPRA rates the expected solve difficulty of 1,000-piece adult jigsaw puzzles. The rating describes challenge—not product quality, safety, or artistic merit.
Two sources of difficulty
Artwork Difficulty measures eight visual factors: color and tonal separability, anchor density and uniqueness, repetition and ambiguity, low-information areas, texture differentiation, boundary clarity, micro-detail ambiguity, and structural predictability. Piece Shape Difficulty is assessed separately from the actual production cut.
Total Solve Difficulty
The piece-cut adjustment is moderated by the artwork’s ambiguity exposure. This prevents the cut from being treated as equally important in every image. The final Total Solve Difficulty score is mapped to one of ten Puzzle Challenge levels.
Independent review
Two evaluators score each eligible submission independently. A third review is required when their results differ materially or lead to different consumer-facing levels. Ratings remain provisional until the production cut has been inspected.