Laboratory screens of usual 8-in-round (20-cm-round) size, in which the diameter of each new wire is equal to the distance between successive parallel wires. Therefore, in a 60-mesh screen (having 60 wires/in (152 wires/cm) measured along either the warp or the woof) the aperture is a square measuring 1/120 in (0.21 mm) on the side. The meshes used are 5, 8, 10, 12, 16, 20, 30, 40, 50, 60, 70, 80, 90, 100, 120, 150, and 200.