Pick Testing of Offset Papers.

The LTF Pick Tester is described briefly. The factors related to picking of paper during printing are discussed. They are: (1) ink film thickness, (2) ink tack, (3) pressures attained in printing, (4) the period of contact between paper and printing element, and (5) the rate at which the paper is separated from the printing element. These factors determine both the forces normal to the paper surface and the period of time during which they act. By simulating press conditions as far as these factors are concerned, the LTF Pick Tester attempts to measure the combination of paper properties that are pertinent in determining pick resistance.