This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
342. In etching the negative you perform work the results of which are just the opposite to retouching or penciling; therefore, before attempting to etch it is essential that you be able to retouch the negative.
343. By means of retouching, shadows are built up and transparent blemishes removed. By etching, you reduce the strong high-lights and subdue objectionable parts which are too prominent in these high-lights, and with the etching knife you may also remove objectionable parts entirely. By the combination of etching and retouching - i. e., by the use of the knife and pencil - you etch and model, and with these two instruments you can make any alteration you desire on the negative. High-lights on the bones in the neck may be cut down and subdued; thick necks made thin; excessive drapery removed; crooked noses straightened; shadows accentuated; hair added; backgrounds altered; objectionable portions removed; figures taken from groups, etc.
The Etching Knife. It is fully as important to have a proper knife, correctly sharpened, as it is to know how to etch. In fact, the greatest assistance will come from a properly sharpened etching knife. Thin, sharp-pointed etching tools are of little use, although some etchers are able to use them to advantage on certain classes of work. The all-around etching knife is one having a large broad blade, made of the very best quality of steel. The handle of the knife should not be long, for it will often be in the way and hinder you from producing results which require a cer-
tain tilt of the knife blade, which a long handle will not permit of; therefore the smaller and more compact the better. An ideal etching tool will be found in the Schrievcr Etching Knife, shown in Illustration No. 20. Both edges of the blade are sharpened, one being slightly curved, while the other is practically straight.
Sharpening The Etching Knife. The very finest oil-stone should be used for sharpening the etching knife. Always wipe the stone very carefully before attempting to use it, for all dust or grit should be removed. The surface of the stone should be perfectly flat. Place a drop of oil on the stone and proceed to sharpen the curved side of the blade first. The blade when properly sharpened should have a somewhat beveled shape - not thin on the edge like a pen-knife or razor. Lay the blade on the stone in such a way as to produce a chisel-shaped edge and draw it forward and backward. Do not move it sideways, as you would when holding a razor or a pocket-knife, but move it lengthways of the blade.
346. While an oil-stone will give you the best results, yet in case of an emergency you may use a piece of very fine emery cloth, fastening the cloth to a small block of wood, A few strokes on the emery cloth hone will generally place the blade in good condition for use. If ground too much, however, you will get a wiry edge, which will scratch and not scrape. If you should get a feather edge do not turn the blade over, for you should never touch the opposite side of the blade to the stone or emery cloth; but by pushing the blade away from you the feather edge will be pulled under and, with a few strokes, removed. Do not draw the blade back heavily, for this would again pull the feather edge out, requiring longer time to remove it.
347. After having sharpened one edge proceed to sharpen the other one in like manner. When sharpening the curved edge the knife may be drawn over the stone in a slightly curved motion, so as to give a perfectly even, sharp edge - one which will not scratch.
348. Remember, that the edge of a retouching knife,
Illustration No. 20 Method of Holding Etching Knife - Schriever Etching Knife See Paragraph 344.
Study No. 5
J. E. Mock
to give good service must be sharp, and when in that condition is quite delicate. Therefore, it must be most carefully handled and not allowed to come in contact with any hard surface except the film of the negative.