(LC) Less Challenging: Larger pieces (1.5" - 2"+), fewer pieces, suitable for all age groups

(C) Challenging: Medium size pieces (1"+), often bright colors, crisp image, 100-250 pieces

(MC) Moderately Challenging: Medium size pieces (3/4" - 1"), multiple piece whimseys, 250+ pieces

(VC) Very Challenging: small size pieces (1/2" - 3/4"), often old images, often much of an image has a large area with same color, 400+ pieces

(EC) Extremely Challenging: smaller size pieces (1/2"), 550+ pieces, repetitive pattern image or muted image colors, complex pieces