Celluloid etching is one of the easiest print processes for the beginner; it yields professional results with a minimum of equipment and experience. The technique is not actually one of etching (which is done with acid) but of engraving or "dry-point," in which the design is incised on a transparent plate of celluloid and printed from this plate on either paper or fabric. The celluloid is easy to scratch or cut and its transparency permits the artist to copy with little difficulty the design which he has created or selected.
The materials needed for making the plate consist of a scriber, or fine etching needle; some ordinary celluloid or some cellulose-acetate material about 0.020 inches thick; a drawing board; a sharpening stone; some thumbtacks; and a piece of white paper. The scriber is made of a pin vise with a point that can be reversed for carrying. The cellulose-acetate material is made especially for etching and may be bought at an art supply house. When choosing the subject for the etching it should be remembered that the final print will be the reverse of the design on the plate. A snapshot, a clipping, a reproduction of a good etching or best of all your original drawing offer good possibilities to the beginner.
Place the picture selected on the drawing board. Lay the celluloid over it (fig. 166). The celluloid should be large enough to allow a 1/2-inch margin on the sides of the picture and 2 inches at the top for practice space. If the celluloid has a tendency to curl, tack it down with the convex side up. Make some practice strokes before starting. The tool must be held absolutely erect at all times. Strokes may be made in any direction. The greater the pressure, the greater the depth and width of the line and the blacker it will print. The correct method of holding the scriber is illustrated (fig. 167). If a line is to be softened in shade run the thumbnail along the line previously drawn with the scriber. A sharppointed knife such as a scalpel may also be used after the worker is proficient with the needle. The resultant line is very clean and smooth. Parts of the design done in this manner will appear sharper or "colder" than work with a needle. Depth in a picture is achieved partly by reducing the size of the more distant objects, partly by scratching them in with lighter strokes. This gives them a grayer tone and heightens the impression of atmospheric depth. Occasionally, insert a sheet of plain paper between the picture and the plate to enable you to gauge the extent of your work. When the plate is completed remove it from the board and score a deep line around the edges of your picture with a ruler and a very sharp knife. Be sure that the scoring is clean cut at the corners. Bend back the edges until they break away cleanly, leaving the finished plate ready for printing.
The plate may be printed in a standard etching press or one devised from a clothes wringer, but entirely satisfactory results can be obtained by hand printing without any special equipment. The first step is the preparation of the paper, which must be soaked in water to soften the fibers. The best papers are those sold specifically for etching, but a good grade of water-color or drawing paper will do about as well.
Take as many sheets as you plan to use and immerse them in a pan of water. A heavy rag paper should soak for several hours, while a wood-pulp paper will be ready for use after a few minutes. When ready to print, place the paper between blotters to remove surplus moisture.
Now squeeze some etcher's ink on a sheet of glass and work it with a paddle or palette knife to a smooth consistency. If the ink is too stiff, add a few drops of plate oil, mixing constantly. The oil and the ink in several colors can be purchased from a printer or at an art supply store.
Make a dauber by tying cotton or soft ravel-lings in a lint-free rag such as a much-laundered handkerchief (fig. 168). Next, fold a piece of tarlatan until it forms a ball with no loose ends. Another wiper should be made of cheesecloth in the same fashion. When not in use the rags should be kept in air tight containers to prevent the ink from drying and hardening. Transfer the ink to the plate with the dauber. Use a rocking motion to roll and press the ink into the lines. Do not twist or scrub with the dauber. When the plate is completely covered, stroke off the surplus with the cheesecloth pad. Grasp firmly in the hand, press it against the plate at one of the lower corners, bend the hand back and push the pad in small circles at an angle of about 45° to the plate. This alternately increases and decreases the pressure as the pad is pushed forward. This movement will require some practice, but is necessary if the ink is to be reduced gradually and evenly (fig. 169).
When the plate has been wiped down exposing the image to the desired degree the circular wiping should be changed to straight strokes across the plate. In finishing use the soft cloth or cheesecloth to remove any spots of ink. A rag very lightly charged with ink is called a "thin" rag; one heavily charged is called a "fat" rag. The latter makes a better print because it leaves a more perfect tone. Hut a thin rag is useful in finishing a wipe where less tone is desired.
The plate may now be printed, but an additional hand wipe will produce an even clearer impression. The motion of the hand is circular and then parallel, as with the rags. To prepare the palm put a slight amount of ink on it with the dauber.
Now place a sheet of the damp paper over the inked plate, cover it with a piece of dry paper and rub this vigorously with any hard, cylindrical object such as the side of a pencil or the back of a comb.
Pressure must be even and care taken not to move the paper on the plate. When the rubbing is completed, lift off the finished print and attach it to a piece of cardboard with gummed tape until dry. This will prevent shrinkage and wrinkling. Re-ink your plate and continue in the same manner until you have as many prints as you want.
After printing, clean the plate thoroughly with turpentine or benzine if you expect to use it again. This must be done immediately, before the ink dries in the lines. Facial tissues are excellent for drying the plates.