GATF examines blankets, torque

GATT's Offset Blankets, Print Quality, and Sheetfed Movement study has concluded that of all blanket variables, proper torque affects print quality the most. In conjunction with seven blanket manufacturers, GATE examined 12 blankets in two print runs with identical usage characteristics, based on

the press, paper, ink, fountain chemistry, speed, plate and temperature. In the first run, all blankets were tensioned to 38 ft. lbs. and printed with a 0.006-inch squeeze between the plate and the blanket. In the second run, two of the blankets were mounted without a torque wrench or packing gauge. The findings showed that while print attributes are only slightly affected by the blanket, torque setting greatly affects tone value. The study also documents trapping and print contrast, discusses sheet movement from unit to unit and shows the effect of various blankets on printing solids and halftones. To purchase a copy of the study, call GATE at 800-662-- 3916 or visit www.gain.net/store to order online from the GAIN Bookstore.

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