Offset Inks-Basic

Offset inks are compounded specifically for use on offset presses.They must be capable to withstand reaction with the press fountain solution it encounters on the dampened offset plate. Ideally, the ink on the ink roller must not absorb water (water-in-ink emulsification),not should the ink break down and mix with the fountain solution on the non-printing areas of the plate (ink-in-water emulsification).Either of these emulsification problems will have a tendency to impair the body, color, or drying qualities of the ink, or trigger tinting on the non-printing regions the plate and printed sheets. The ink being used on an offset press needs to be competent to hold the full-intended color and covering power to the paper even with the split-film action. This happens for the reason that offset blanket picks up only a small percentage the ink from the plate and delivers only a portion of that to the paper. The film of ink getting the plate, then,is very light, and the ink must be competent to show its full color and opacity with this film.