This is a specially made film test pattern that can tell you the correct mesh count for a screen that’s not marked. Two different scales are used for monofilament fabric, one for mesh counts from 100 to 240, the other for counts from 200 to 480. There is also a third test image for 55dpi to 200dpi halftone dot patterns that effectively tells you how many halftone dots-per-inch.

Directions for use: Place the test pattern film on your screen face down and pivot on the mesh surface; a wide “bar pattern” forms that centers on the actual mesh count in question; read the number that’s listed to the side of that bar for that screen’s mesh count.