The offset press is more delicate than the etching and direct lithographic
The paper bed: DO NOT ADJUST!
Do not adjust the paper bed. Adjustments in the height of this bed
impact all subsequent printing.
Adjusting the "stone" bed. The bed used to hold the printing element is highly adaptable. It can hold lithographic stones, linoleum, Plexiglas, and the aluminum plates normally used for photo-lithography. Each turn of the four large adjustment screws moves the bed up or down one (twelfth?) of an inch. The bed needs to be adjusted to accommodate various printing elements and needs to be adjusted on all four sides. Follow the chart below to arrive a position slight below ideal, and adjust the bed upward by fractional turns until oil or ink transfers evenly from all four corners of the printing element. (Note: if you are working in lithography this is best done while gum is covering the stone.)
The term "on impression" means that the impression cylinder is in it lower position and able to pick up or deposit ink.
Stone-Bed adjustments / small adjustments
1 revolution equals .083 of an inch (1/12th inch)
1/2 revolution equals .042 of an inch (1/24th inch
1/4 revolution equals .021 of an inch
1/8 revolution equals .011 of an inch
Adjustments below this (for all four corneres) should be made in the impression adjustments. Rather than bed adjustments.
approximately equal to a photo-plate
1/16th revolution equals .005
Stone-Bed adjustments/ larger adjustments
Never turn one adjustment screw more than three revolutions with out adjusting others to match.
2 revolutions .equals 1/6th inch
3 revolutions .equals 1/4 inch
6 revolutions .equals 1/2 inch
12 revolutions equals 1 inch
Clean up process:
When printing or cleaning up: no hands or other material on the
Water is not to remain on the steel portions of the press any longer than necessary.
Clean and prevent rust:
Steel parts should be rubbed down with thin past wax or rust inhibitors such as WD-40 and the gears should be free of foreign material. Fragments of broken stone, paper scraps, string and fibers from fabric do not belong in the gear races or on the blankets.
The blankets are expensive and they are crucial to successful printing. Inks will eventually stain them but their appearance indicates their health. Blankets should be cleaned with blanket wash and occasionally with glaze remover. After cleaning, they should be rubbed down with talc.
Do not use hand cleaner, alcohol, scouring powder, or soap on the blankets.
Lithography requires the best available blankets. Relief printmaking
and monoprints dont require the same blankets and are more likely to
damage blankets. Use blankets that are no larger than necessary. Select
a blanket that is wider than your image and paper.