A powder, commonly consisting of fine starch particles that range in size from 15:65 microns, sprayed on the surface of printed sheets either to prevent ink setoff—the transfer of wet ink from a printed sheet to the back of the sheet lying on top of it—or to prevent a printed ink film from contacting the wet printed ink film on the back of the sheet above it. Anti-setoff spray is also referred to as spray powder. The use of anti-setoff sprays is undesirable on the part of many printers, and ink manufacturers have taken to incorporating anti-setoff compounds directly into the ink itself. (See also Anti-Setoff Compound.)