The primary function of anti set-off powders is to form a separation between the sheets of stock as they leave the press.  This separation traps air between the sheets to speed ink drying.  It also breaks the suction effects of wet ink and static and prevents the ink from setting off onto the sheet above.  This spray's ability to perform this function is a result of a combination of particle size, density and the number and nature of particles applied.  The largest users of anti set-off powders are folding carton printers, followed by label printers, large letterpress printers, flexographic printers and large offset printers.  Usually, as the weight of the printing stock increases, the recommended particle size also increases.

WHEN DO YOU USE COATED POWDERS, OR REGULAR POWDERS?

This data should help you identify the best first choice spray powder.

Coated spray powders represent the vast majority of applications.  Select coated powders for large corrugated printers, folding carton manufacturers, most four color work done on four color presses and most large sheetfed printers that run large heavy lifts of paper.  The grade of coated spray powder is determined by the weight of the paper stock, type of printing and spray equipment.  As a rule of thumb, the grade of coated powder (and the micron size) increases as the weight of the paper stock or height of the stack increases.