TABLE OF CONTENTS
Printing press. Set of etching blankets. Printing paper. Etching ink. Rubber inking roller. Two yards mosquito netting. Small pane of glass for inking slab. Roll of 1-inch-wide gummed paper.
THE ETCHING PRESS
All etching presses are constructed along the same basic principles , though they vary considerably in size from small table presses to large professional presses. Some presses are geared to make them manually easier to operate. The press consists of a framework which supports two rollers. A bed rides back and forth between the rollers. It rests on guides which keep the bed moving in a straight line and on one level. At the top of the frame are two hand screws for adjusting pressure on the upper roller. These are the pressure screws. The handles used to turn the press consist of a single bar or a crossed set of bars or, in a geared press, of a wheel and handle. The geared press is the most expensive type. For most printing, a table press is adequate. The superior pressures possible on the larger presses are needed only to meet exceptional printing requirements. For anyone considering the purchase of a press there are two important dimensions to bear in mind-the width and diameter of the rollers. The width of the roller is generally identical with the width of the bed. A good, general, working-size table-model press has a 14- or 16-inch bed and roller. Presses smaller than this do not usually develop sufficient pressure for satisfactory printing. The diameter of the roller should be a minimum of 4 inches. The larger the diameter, the better printing will result. Thinner rollers simply curl up the plate. (Should this occur, the plate con be flattened by sending it upside down between blotters through the press.) While a good press is vital to good printing, I have seen amateurs get surprisingly fair prints by using a wooden clothes wringer when it was impossible for them to get anything better.
A fine etching press can be made out of a second-hand pleating machine. This furnishes the frame, the rollers, and the gears. With the addition of a bed, guides, and hand screws, one has the complete press.
Care of the Press
Most presses are sturdily constructed. There are few moving parts. A little care will preserve the life of a press indefinitely. The oil blocks, which support the rollers, should be oiled frequently. The bed guides should be greased or oiled. Any rust spots which appear on the rollers should be removed immediately with emery paper. Pressure adjustment should be kept at the minimum pressure that will give a good print. The plate will last for many more prints if the pressure is kept to a minimum. Never force the pressure on the press unnecessarily. A cracked frame or roller axle can result, which will involve expensive repairs.
THE ETCHING BLANKETS
Etching blankets can be bought in any store that sells piano felt. Good etching blankets are necessary for good printing. The best grade of piano felt is generally used. The blankets must be soft and fluffy so that they are flexible enough to be pressed by the rollers into the lines in the etching plate. Two blankets are needed-a face blanket and a backing blanket. The face blanket should be about 1/4 inch thick, the backing blanket about 1/2 inch thick. Blankets are cut to fit the bed of the press, about 1 inch narrower than the width of the bed and a few inches shorter than the length of the bed. It is desirable to have two sets of blankets, alternating the sets on the press frequently. Blankets get stiff and hard through absorbing sizing from the printing paper and because they are under constant pressure from the rollers. When blankets get hard or dirty, they can be washed in lukewarm water, using any fine soap flake. Hang them by two clothespins to dry.
BEVELING PLATE BEFORE PRINTING
When an etching plate is purchased, the edges are unfinished. Usually they are sharp enough to damage the etching blankets if printing is attempted before beveling the plate. Filing should be done away from the printing and inking areas. Metal filings can seriously scratch the surface of the plate if they are picked up by the wiping rag. Use a fine-tooth file and carefully bevel the edges and corners of the plate. Then wash the face and back of the plate thoroughly under a faucet. The plate is then ready for the press.
SETTING THE PRESSURE FOR PRINTING
Release the pressure on the rollers by loosening the hand screws. Roll the bed out to one side of the press as far as it will go. Place the blankets on the bed, the face blanket first and the backing blanket over it. Roll the bed back until the roller rests on both blankets. Tighten the pressure screws, using firm pressure. Fold a blotter in half and cut it down to a size somewhat larger than the plate which is to be printed. Place the folded blotter in the center of the bed. Place the uninked plate face up on the lower half of the blotter and cover it with the top half of the blotter. Cover the blotter with the blankets. Run through the press. Do not run the rollers off the edge of the blankets. lift the blankets and examine the blotter. The top half will show an impression of the back of the plate, the intaglio. On the inside of the blotter there should be a clear impression of the face of the etching. If the pressure is too light or there is uneven pressure on either side it will be evident at once. If the pressure on one side is weak, the impression of the lines will be weak or will not register at all on that side. Good pressure adjustment will result in a full, clear impression on the blotter of all the work on the plate. Adjust the pressure as needed and repeat the test printing until the pressure is satisfactory. The press will then be set for printing. Once it is correctly adjusted it is advisable to leave the pressure setting alone. New adjustments for each plate are not necessary. Occasionally, however, an unusually thin etching plate will demand new adjustments.
INKING AND WIPING THE PLATE
Any electric or gas stove can be used to heat the etching plate for inking. An open flame on the back of the plate focuses the heat on a limited area only. A general distribution of heat over the whole plate is much better. The best type of stove is a small, gas-burning, solid, rnetal-topped stove-the kind generally used as a frankfurter gridelle. This permits close control of the temperature and afforels a wide even distribution of heat. The next best is a similar stove, electrically heated, with low, medium, and high heat controls. The ordinary cooking stove in the kitchen will do quite well, if a metal plate is used to cover the open burner.
A table top or any,flat surface such as a sheet of glass can be used for an inking surface. It should always be kept clean. Grit or dust picked up by the roller or wiping rags can be injurious to the plate. The stove should be set for a medium heat. A very hot oven can burn the ink. Place the plate on the stove and squeeze a few dabs of printing ink on the face of the plate. Using the inking roller, roll the ink out over the plate. Use firm pressure so that the ink is forced into all the incised areas of the plate. If the plate gets too hot during inking, remove it from the stove and continue rolling.
Wad a large piece of mosquito netting into a loose ball, large enough to fill the hand. (Do not pack it into a tight, small ball.) Begin wiping the plate with the pad of netting, using firm pressure and wiping with a circular motion. This circular motion is important because it keeps the ink from being wiped out of the lines. As the wiping pad gets loaded with ink, keep changing to clean areas. Use lighter pressure in wiping as the plate gets cleaner. Wipe the surface of the plate absolutely clean. Unwiped smudges will disfigure a print, and a dirty wipe means a wasted print. When the plate is wiped clean, use a piece of cheesecloth to take the ink off the edges of the plate. The plate is now ready for printing.
THE PRINTING PAPER
For the beginner, almost any available paper will do for printing paper. Good prints can be made on cheap charcoal drawing paper. For the advanced etcher, the choice and preparation of paper play an important part in the success of the print. A good grade of rag paper gives the best results. Rag paper comes in a wide range of finishes and weights. It ranges from Soft, absorbent, rough-surface sheets to hard, smooth, glossy-coated vellums. Occasionally one can find beautiful handrnade papers in old books or ledgers. Even when they have a very rough-textured surface, this roughness is flattened out under the pressure during printing. A soft paper, like Rives, is preferable for printing plates which are all bitten-line work. For dry point or aquatint, with their subtle nu- ances of tone, the harder, smoother Japanese vellum is more sensitive. All etching papers must be softened before printing. The blankets, under the pressure of the rollers, must be able to mold the paper into every incised line on the plate. Dry paper is too stiff for this. Run a few inches of water into a large tray or into the bathtub. Sink the paper under water, a single sheet at a time, otherwise the sheets stick together and do not get properly soaked. Different papers require different lengths of time in the bath for softening. Charcoal paper is ready in 5 minutes, Rives requires at least 1 hour, while Japanese vellum takes 24 hours of soaking. The correct soaking time for each paper will be found through experimentation. The paper should be removed from the bath only one sheet at a time, after the plate is inked and ready for the press. The paper comes out of the tray shiny wet. All excess water must be blotted off. Place the sheet between blotters and rub until the shine is gone. If the paper is too wet it will repel the greasy ink; if it is
In order to protect the blankets, it is advisable to place the plate and paper between blotters when printing. After more experience, you can eliminate the blotter's for more sensitive impressions, but be sure to place a sheet of newsprint over the printing paper to absorb the sizing. Fold a large white blotter in half. Cut this down to the size of th e paper to be used in printing. Flip the blankets back over the top roller. Place the blotter on the bed of the press. Slightly warm the plate, which has been inked and wiped. Place it face up on the lower half of the blotter. Holding the printing paper by two diagonally opposite corners, place it in position over the plate. Drop the upper half of the blotter on the paper. Pull the blankets down over the blotter. Smooth them to be sure there are no wrinkles. Send through the press. Examine the first print carefully before pulling any more prints to see that no corrections are needed.
The plate does not have to be cleaned between prints, but it must be reinked and rewiped for each print. After printing is completed, all ink must be meticulously cleaned off the plate. Ink left in the lines will harden and become difficult to remove. Should this happen, use a toothbrush and turpentine or paint remover to scrub the ink out of the lines.
DRYING THE PRINTS
The damp prints must be stretched or pressed while drying; otherwise the paper will remain buckled or curled when dry. The prints can be pressed flat if they are stacked in a pile with a sheet of newsprint or a blotter between each one. A drawing board and a weight placed over the pile will hold the papers down. The wet ink will offset a little, but this will not injure the print. If you wish to avoid offsetting, you can stretch the prints for drying. Place the prints, face up, on a drawing board or any rigid panel. Use gummed paper to glue all four edges down to the board. As each print dries, it will stretch tight, and when cut loose after drying it will remain flat.
Referenced from Modern Methods and Materials of Etching By Harry Sternberg