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Old And Sold Antiques Digest Article

Etching

[Etching]  [Dry-Point (pointe-seche)]  [Preparing The Plate For Acid]  [Drawing On The Plate]  [Biting The Plate]  [Reworking Ground]  [Soft Ground]  [Aquatint]  [Mezzotint]  [A First Experiment In Etching] 

( Originally Published 1917 )



DRY-POINT (pointe-seche) is a method of engraving on copper with a hard and very sharp steel point. Although it is a misnomer to call it etching, as no acid is employed, yet custom sanctions the use of the word. In etching, the copper is dissolved to make the line; in dry-point it is dug out. The steel point in cutting the copper turns up a furrow known as the burr. If this is left on it catches the ink and gives that velvety richness and softness which we associate with dry-point. The burr may be partly cut off with a sharp scraper, or it may be entirely removed, as is generally the case when dry-point is used in connection with etching. Dry-point needles are usually made of extra hard steel and are of varying sizes.

The needle should have a shorter cone than the etching needle and a sharp point. Diamonds are often used in dry-point, their great advantage lying in their always being sha_-p. However, they have this objection, that they are brittle, and should not be used in the heavier passages. The dry-point needle can make very faint lines, and it is therefore good for putting in the delicate lines of sky. Light dry-point lines harmonise well with etched lines, whereas deep ones do not. It is wise therefore to add drypoint only in the distant or the lighter parts of an etching. Much dry-point added to an etching decreases materially the number of satisfactory prints. The needle when held upright throws up an equal burr on both sides of the line. When held slanting it throws up a much heavier burr for a given pressure, and so is more effective. To see your work, rub some lampblack mixed with oil into the lines and wipe off with a rag.

Dry-point is much simpler than etching proper, as the uncertainty of the biting with acid is avoided and the work can be easily seen. The play of the needle on the plate is less free in this method than in etching, on account of the pressure required to cut into the copper. To sum up, the distinctive characteristics of dry-point are: velvety richness and softness of line, arising from the action of the ink on the burr, and lack of perfect freedom in the line, owing to the resistance of the copper to the point.

Sir Seymour Haden discovered that Rembrandt's etchings could be divided into three periods of about ten years each-the first period, pure etching; second period, etching mixed with dry-point; third period, pure dry-point.

Soft Ground.-This is a method of drawing on a plate with a lead pencil. The ordinary etching ground mixed with tallow to soften it is put on the plate in the usual way. A sheet of grained tissue paper is stretched over this ground. The design is then drawn on the tissue with a pencil. When the paper is removed, it will be found that the ground has adhered to the paper wherever the pencil has been. The lines thus left on the copper are bitten in the usual way. The resulting print resembles a soft pencil drawing or a lithograph.

Aquatint is engraving with tones instead of lines. A plate is covered with finely powdered resin and the tones are produced by the stopping out method. Sand grain is a kind of aquatint where the grain is produced by running a plate, covered with an ordinary ground and on which a piece of sand paper has been placed, through an etching press.

Mezzotint is a means of engraving in tone. It has been much used for the reproduction of painting. Neither lines nor acid are employed. A copper plate is uniformly roughened by going over it in many different directions with a toothed instrument called a rocker. A rocked plate would print a uniform black. A steel tool called a mezzotint scraper is used to reduce the roughness and get the various tones, working from the dark to the light. An outline of the organic parts of the design is sometimes rather deeply bitten on the plate before rocking. Most interesting examples of this are Turner's beautiful outlines for the plates of the Liber Studiorum. Mezzotint is much richer than charcoal drawing, which it somewhat resembles. On account of the burr in mezzotints, it is only possible to get a comparatively few good impressions; twenty or thirty are all that are usually printed without steel facing.

Monotype.-If a picture is painted on a polished copper plate and the plate, covered with a dampened piece of etching paper, is run through an etching press, or even through an ordinary washing mangle, the resulting impression is known as a monotype. In theory only one print can be taken, but in practise a second or even a third are often more interesting than the first. Some amusing results are attained, but it is not a method to employ for serious work. It is an artistic plaything and the effects are accidental. Colour may be used, but more often the drawing is made with black ink.

Glass Prints.-This is another process with which artists have amused themselves. A sheet of glass is covered with an opaque varnish on which a drawing is made with an etching needle. A print can be made by exposing sensitized paper to the light behind this plate-the Barbizon painters made many glass prints. Neither glass prints nor monotypes are in any sense engravings or etchings.

LIST OF MATERIALS FOR ETCHING

Plate
File
Vise, with handle
Turpentine
Whiting (Blanc d'Espagne) Ammonia
Dabber
Ball of Etching ground
Wax tapers (Rat de cave)
Etching needles
Varnish for back of plate Tray for acid
Acid
Blotting paper
Stopping-out varnish
Water-colour brushes
Scraper
Burnisher
Olive Oil
Charcoal
Dry-Point Needles
Oil Rubber
Graver or Burin
Roller
Chamois skin
Oil Stone
Snake Stone
Emery Paper
Lamp Black Anvil
Hammer
Callipers.

In addition one should be provided with feathers, running water if possible, means of heating and clean cotton rags.

The Plate as it comes to the etcher is polished but needs to be bevelled on the edges and corners so that it will not cut the paper when printing. Use i8-gauge American etching copper for ordinary work. For mezzotints or large etchings use 16 gauge. English copper is preferred by some and may be had in New York. Old hand-hammered copper is desirable but very difficult to procure. Zinc plates are much cheaper than copper. They require a different proportion in the acid. The beginner would do well to use copper.

The File is used to bevel the edges and corners of the plate.

The Vise should have a wooden handle and one of the jaws should be covered with a piece of an old kid glove to protect the surface of the plate.

Turpentine is used to clean the plate and for removing the ground after the biting is finished.

Whiting softened with Ammonia is rubbed over the plate with printing muslin for further cleaning. Electro Silicon or Gilder's Whitening are good for this purpose. If the plate is tarnished vinegar and salt are sometimes used.

The Dabber is easily made as follows: Cut a disk of stiff cardboard about three inches in diameter. Lay a piece of silk, twelve inches across, flat on a table. On this, make a pile of cotton wool and horse-hair, on top of which place the cardboard. Draw up the silk around the disk and tie with a string. Cut off the ends of the silk, leaving enough for a handle. Sometimes fine kid or chamois skin is used instead of the silk.

Etching Ground.-A good etching ground should resist the action of the acid perfectly. It should adhere to the plate so well that it will hold up even when a small amount is left between closely drawn lines. The lines should be clear cut with perfect edges. The ground should not be so hard that the needle will not expose the copper under ordinary pressure. In other words, the ground should be so good that the etcher need not give it a thought.

COMPOSITION OF ETCHING GROUND

Bees-wax (pure) .......................2 1/2 ounces

Syrian Asphaltum ....................... 2 ounces

Burgundy pitch ......................... 1/2 ounce

Black pitch ............................1/2 ounce

GROUND KNOWN AS REMBRANDT'S

White Wax .............................30 grains

Gum Mastic ............................15 grains

Asphaltum or Amber ....................15 grains

BOSSE'S GROUND AS USED BY HAMERTON

Bees-wax (pure) .......................5 ounces

Gum Mastic ............................3 ounces

Bitumen (in powder) ...................1 1/2 ounces

This ground is used for the Dutch mordant.

MODIFICATION OF BOSSE'S GROUND USED BY PATON FOR NITRIC BATH

Bees-wax (pure) .......................3 ounces

Gum Mastic ........................... 1 ounce

Burgundy pitch ........................1 ounce

Bitumen (in powder) ...................1 ounce

Increase the amount of Asphaltum in the Rembrandt Ground to 30 grains for summer use. Some etchers add a small ball of concentrated solution of rubber to the above formulas.

Making Etching Ground from formula given first.-First powder the pitch and the asphaltum. The black pitch is added for colour only. If this is omitted, twice as much Burgundy pitch must be used. Put the beeswax into a glazed double boiler and melt over a slow fire. Add the Syrian asphaltum and stir with a glass rod. Next add the pitch, making sure that each ingredient is melted before the next is added. Take the pot off the fire when putting in asphaltum, as it is liable to ignite. A good plan is to keep at hand a copper plate larger than the dish to put over the boiler in case the asphaltum does catch on fire.

Let the mixture simmer for fifteen minutes stirring all the time. Pour into a pail of warm water and when cool enough form into balls squeezing out the water. Cover with a bit of silk cloth and it is ready for use.

Wax Tapers.-A twisted bundle of wax tapers, known as the "Rat de Cave," is used for smoking the plate. These may be had of any dealer in Etching supplies.

Etching Needles are usually made with wooden handles. Sometimes the handle is adjustable so that a number of points of different sizes can be set in as required. The disadvantage of these is that they may work loose in time. Good etching needles are also made of one piece of steel. The extra weight helps in cutting through the ground. Needles sharpened at both ends are to be avoided as they are somewhat dangerous if carelessly used. Large sewing or darning needles make good etching points, provided a firm wooden handle can be devised. I have a number of very successful etching needles made from broken dental tools. An etching needle should be sharpened to a conical point slightly blunted. It should not scratch the copper but go equally well in all directions, gliding on the copper and not digging into it. To sharpen the needle, place it between the palms of the hands and holding the point at an angle on the oilstone rub the hands together. Describe circles of varying sizes on a sheet of cardboard to polish the point. Do this until the point will glide on the thumbnail without catching.

Dry-Point Needles are the same shape as etching needles, but are of much harder steel. They are made very sharp for cutting the copper.

Asphaltum Varnish or French Polish is used for painting over the back and sides of the plate to protect it from the acid.

The Tray for Acid can be of porcelain, enamel ware, or any flat-bottomed dish that is impervious to acid. In Paris, trays of papiermache, covered with many coats of Brunswick Black, are to be had. They are liable to leak, as I have found to my sorrow.

Acid.-The principal acids used in etching are nitric, hydrochloric and perchloride of iron. All acids should be kept in bottles, with ground glass stoppers, in a safe place. Work before an open window when using nitric acid as the gas given off is injurious to the throat and eyes. Acid will turn the clothing or the skin a bright yellow. Some etchers add a small piece of sal-ammoniac to the bath before biting, to make it work more smoothly. Use a piece the size of a hazel-nut to a pint of acid. The colour of the acid is clear and slightly yellow until the copper is laid in it, when it becomes green. For copper, the proportion is three parts of pure nitric acid of a specific gravity of r.4a and 5 parts of water. Many use distilled water. For zinc or steel one part of acid to seven parts of water should be used. Never use the same acid for zinc and copper.

In mixing, always remember to add the acid to the water. It is dangerous to pour water into acid. As the chemical action generates heat the mixture should be allowed to stand for several hours. It is a good plan to put a strip of copper or a copper coin into the acid before using. This makes it work better. Always have beside the bath a basin of clean water to wash the plate in and also to wash off any acid from the fingers. Have a bottle of ammonia handy, in case acid gets on the clothes. Be sure to get nitric and not nitrous acid, for the fumes from the latter are much more disagreeable, and, as the acid is not as strong as nitric, the proportions given will not hold. Sir Frank Short uses acetic acid instead of water in the nitric bath.

DUTCH BATH

The Formula for Dutch Bath is:

Hydrochloric acid ................. 10 parts by weight
Chlorate of Potash .................... 2 " " "
Water .................................88 " " "

Take half of the water hot and dissolve the potash. When cold add remainder of water and hydrochloric acid. The chemical action will heat the mixture again. The proportions of the Dutch bath may be varied.

Smillie used:

Muriatic acid .......................... 1 ounce
Chlorate of Potash .....................1/5th ounce
Water ................................. ....5 ounces

The Dutch Bath is useful for starting a plate as it attacks all the lines evenly, whereas nitric acid sometimes plays tricks by starting some lines before others. With some plates it is a good plan to bite the distance in the Dutch and the remainder in the nitric. When you are doing the whole plate in the Dutch, it is a good idea to give it one bubbling all over in the nitric before removing ground. For extremely fine, close and delicate work use the Dutch bath cold. This bath is very slow in action compared with the nitric and bites deeper into the plate for a given width of surface. The bath should be heated to from 7o to go'. The usual temperature is about 80. Use a thermometer to keep the same degree as the rate of biting varies with the temperature.

The above is the mordant used for working directly in the bath. When employing this method, begin by drawing the lines of your subject which are to be the darkest and work toward the light. It is more difficult to see the work than with nitric because the Dutch turns the lines nearly as black as the ground. A time-gauge can be made in the following manner: A strip of copper having on it a series of lines can be bitten 1/2, 1, 2, 5, 10, 15 20, 30, 40, and 60 minutes to use as a guide, noting the temperature and employing the same when biting the plate. One of the advantages of the Dutch bath is that no unpleasant and injurious fumes are given off.

Perchloride of Iron is used pure as a mordant. When the plate is taken from this bath it should be washed in water and then in a weak solution of nitric acid. Wash again in water before putting back in the perchloride. This method will give the best results. One of the advantages of this acid is that there are no injurious fumes. The resulting line resembles the Dutch.

Kind of Line resulting from different baths.-Nitric line is wide with a ragged edge and more V-shaped. The Dutch mordant bites deeper and afterward sidewise. At first it is like a shallow "U" and in deeper biting it takes the form of an inverted Moorish arch. Deep lines therefore hold more ink than would appear from the width of line on the surface.

Stopping Out Varnish.-Japan Black thinned with turpentine is a good stopping out varnish, but takes too long to dry. Hamerton recommends a saturated solution of white wax in ether, adding % part of Japan varnish. Chloroform can be used instead of ether. Another good mixture is of Asphaltum varnish mixed with some old etching ground. Sir Frank Short recommends etching ground dissolved in chloroform or benzol. The above formulas are to be used when you may wish to draw over the ground. For ordinary stopping out use any varnish that is impervious to acid and quick drying. Rhind's quick drying stopping out varnish is excellent. Penrose Mogul Varnish is quick drying, acid resisting and not brittle.

Scraper.-This triangular tool has three cutting edges which must be kept sharp all the time or they will scratch the plate. It is used for scraping the surface of the plate to reduce over-bitten lines. The scraper is also used to remove dry point burr. It should be very sharp for this purpose as sometimes one wishes to remove only the top of the burr. Should the scraper be used too much on any one part of the plate it will cause a depression which will hold ink.

Hammer, Anvil and Callipers.--A depression is remedied by knocking up the plate from the back by means of a hammer and polished anvil. A map of the depression can be drawn on the back of the copper by using a pair of long-armed callipers, one prong of which is sharpened to scratch the back of the plate. Be careful not to knock up. the plate too much or it may buckle.

Burnisher.-This is also used to reduce over-bitten passages. It consists of an ovalshaped piece of highly polished steel set in a wooden handle. The tapering point is the part used in reducing the lines. It is held at an angle to the plate and passed diagonally across the lines, thus partly closing them so that they hold less ink and will print lighter. The burnisher is a most useful tool, and in the hands of an expert can be made to perform wonders. Some etchers over-bite certain passages purposely to get the exact tones with the burnisher. To keep the burnisher in good condition rub it back and forth along a groove in a piece of wood in which some emery powder has been placed. Tripoli powder and olive oil are also good for polishing the burnisher.

Graver or Burin. This is a tool which must be sparingly used in etching. It is useful to strengthen a weak line, following each irregularity. To slightly rebite lines which have been gone over with the burin restores the quality of the etched line. Avoid employing the burin in the stiff manner of the engraver.

Charcoal.-Willow Charcoal in sticks is used to polish the plate and reduce over-bitten passages. It comes in varying degrees of hardness and is used with water as well as olive oil.

Oil Rubber.-An Oil Rubber is made by binding tightly a roll of old printing blanketing. The roll is usually about 6" long by 2" in diameter. The end is used with oil for polishing the plate.



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