Practical notes on etching

Contents

CHAP.

Introduction

I. Choosing the Plate .

II. Cleaning the Plate .

III. The Etching Ground

IV. Laying the Ground .

V. Colouring the Ground

VI. The Needle ....

VII. Needle-work

VIII. Methods of Working

IX. Mordants ....

X. After-Processes .

XI. Printing ....

XII. Conclusion ....

PAGE

I

LIST OF ILLUSTRATIONS.

PAGE

The Barn-door . Frontispiece

The Tryst (first-state) . 26

The Barn-door (Jirst state) . 28

The Larch Wood (wiped) . • . 30

The Brook . 32

The River Llyfnant (dry-point) . 48

The Tryst . 50

The Larch Wood (with retroussage) . 64

PRACTICAL NOTES ON ETCHING.

INTRODUCTION.

The following chapters upon the practice of Etching appeared originally for the most part in the pages of “ The Etcher,” and they were written under the impression that the experi¬ ence gained during many years of practice might afford useful hints for the guidance of novices in the art. It is true that there has been no lack of valuable treatises upon etching. Not to speak of earlier and now, perhaps, somewhat anti¬ quated works, the recent writings of Haden, Hamerton, and Lalanne — all of them practical etchers — might seem to have embraced everything that could be usefully said upon the subject. Yet no less true is it that the difficulties of a manipulatory art often vary with every operator who prac¬ tises it, and that although a writer may seem to himself to have forestalled every possible occasion of error, there may yet remain many upon which he has failed to touch, owing to the fact of their never having presented themselves as diffi¬ culties in his own practice. Be this as it may, it appeared to the writer that, in spite of all that has appeared upon the subject of etching, there were still some branches of it upon which it might be useful to enlarge, and while it has been his endeavour to give a sufficiently full and clear account of all the principal methods of proceeding now in vogue, together with such modifications of them as he has been led to intro¬ duce in his own practice, he has treated some parts of the subject — such, for instance, as that of needle- work — with a

B

PRACTICAL NOTES ON ETCHING.

degree of fulness not hitherto attempted. Judging by his own experience of the errors into which beginners are liable to fall, some hints upon the management of the needle appeared to him by no means superfluous, although they may simply embody conclusions to which, in their absence, the etcher’s own practice would sooner or later guide him.

The subject of mordants was also one which appeared to deserve some amplification. The etcher having found a mordant to his liking, and to the use of which he has become accustomed, forbears, as a rule, to trouble himself about any other. Hence it is rare to find any one who has much prac¬ tical acquaintance with the characteristics, various as they are, of more than one. Some comparison, however, of those generally in use seemed desirable, and this, partly from his own experience, partly through the kindness of friends whose practice has differed from his own, the writer has been enabled to supply. He trusts, in short, that in the following pages many hints respecting the minutiae of the etching process may be found not previously touched upon. There are probably few workers upon the copper who have not met with difficulties in practice, to overcome which they have been driven to devise their own expedients. There must be many whose experience, if recorded, would not fail to be both interesting and instructive, and to afford valuable hints towards surmounting the obstacles which beset the young etcher’s path.

I. — Choosing the Plate.

Among the essential preliminaries to successful etching, the first to be considered is the proper selection of the copper plate. Unfortunately, this is by no means so easy a matter as may appear ; for there may be fatal defects in a plate which the closest scrutiny fails to detect, and which only reveal themselves after the copper is worked upon.

Sometimes, when a plate is very imperfect, a certain

CHOOSING THE PLATE .

mottled appearance, due to the presence of a multitude of minute ramifying lines, may be observed. The copper is said to be spongy, and in this case should be unhesitatingly condemned. Were it to be etched upon, and a proof to be taken, it would be found that each of the above-mentioned lines would make its mark upon the paper, to the entire destruction of anything like purity in the lights of the pic¬ ture, and that with every successive impression the defect would become more manifest. Not unfrequently, however, a plate which appears to the eye perfectly sound is in reality deceptive, and soft, either altogether, or in patches. In the former case the mottled appearance above referred to, though not at first observable, will, after a very few impressions, begin to show itself, with all its attendant disadvantages ; and in the latter there will be the additional annoyance of uneven biting, as the rate at which the plate is acted upon by the acid depends upon the density of the metal.

The question naturally suggests itself whether there are no means by which the etcher can test the copper plate before purchasing.

With this object in view, some etchers try the ring of the plate by balancing it on the outspread tips of the fingers of one hand, while striking it with the other. It is said that the sound will vary according to the density of the metal, a soft plate yielding a more muffled tone than a hard one. Probably to a practised ear this may be a satisfactory test, but it can hardly be relied upon in the hands of a person unaccustomed to its use.

Perhaps the best available test — though it is by no means a crucial one — is afforded by the appearance of the back of the plate. In former days, before the introduction of modern machinery, all coppers were consolidated by hammering — a process which left its mark in the battered appearance . of both sides of the plate. On the back of the plate this remained, and afforded evidence of its history ; on the front it was, of course, obliterated in the after-processes of planing

PRACTICAL NOTES ON ETCHING.

and polishing. In the present day many coppers, instead of being hammered, are simply passed between heavy rollers, as is shown by the smooth, unbattered state of the back. The pressure thus brought to bear upon them is, indeed, enormous, but where the plate is of unequal density, it fails to consoli¬ date the weak places, and plates which have been so treated cannot be relied upon with the same confidence as those which have been hammered.

On the whole, the best advice to be offered to the young etcher, in reference to the selection of his plates, is, that he should be careful to deal with a firm of high respectability, and that he should insist on having the plates thoroughly hammered — noting well the state of the back of the copper. He will have to pay a rather higher price for them, but the increased security and durability are really worth the addi¬ tional outlay. M. Lalanne recommends that the plate should be purchased thicker, but of somewhat smaller size than required, and hammered out until the proper size is attained — a course which will insure the metal being thoroughly consolidated. But this does not apply to “ spongy " copper, the defect of which is irremediable by hammering or any other treatment.

II. — Cleaning the Plate.

Before proceeding to apply the etching ground to the plate, it is necessary to remove from the surface of the latter every trace of grease, which, if allowed to remain, would prevent the etching ground adhering firmly to the plate, and cause it to break away in patches. There is nothing better for its removal than rectified spirit of turpentine applied with a soft rag. Whiting and other powdery substances sometimes recommended seem undesirable on the score of dust.

Some etchers are careful also to remove from the copper all marks of tarnish. The necessity for this, if it ever exists, seems to do so only where the etcher adopts the principle of

CLEANING THE PLATE.

not allowing the needle-point to penetrate the surface of the copper; and it arises from the fact that copper, when tar¬ nished, is less readily attacked by the mordant than it is when bright, and in order to obviate the unequal biting which the presence of tarnish would thus involve. The removal is easily effected by plunging the plate into a bath of pure hydrochloric acid, or by the application of water slightly acidulated with nitric acid.

Both grease and tarnish may also be conveniently removed by rubbing the plate with willow charcoal. The charcoal, of which a tolerably broad piece should be chosen, should be cut at an acute angle with the grain, and the surface thus obtained should be placed flat upon the copper, under water. It should then be driven, gently but steadily, from end to end of the plate in single, even strokes, after the manner of a carpenter’s plane ; the result of which will be, that the old surface of the copper, with all its impurities, is removed, and a new one substituted, uniformly marked by a multitude of exceedingly minute striations due to the grain of the char¬ coal. The plate, if printed from in this state, should yield an even tint of delicate grey. In those passages in which the artist may desire the pure white paper to be seen, the stria¬ tions are afterwards easily removed, and the original polish of the copper restored by the use of the burnisher ; or the whole surface of the copper may be repolished with crocus powder and sweet oil applied with a piece of soft flannel. Another advantage resulting from the use of the charcoal is, that the striated surface of the copper affords better holding for the etching-ground than a polished surface would give.

III. — The Etching Ground.

The plate, having been cleaned as previously described, should now be coated with the etching ground, and it is in some respects desirable that this should be done before the copper has had time to become tarnished by contact with

PRACTICAL NOTES ON ETCHING.

the air — an effect which the impure and smoky atmosphere of the town soon produces.

Etching ground which may generally be relied upon, but the constituents of which are known only to the maker, may be purchased; and the following observations are intended for those who, acting upon the maxim that “ if you want a thing well done, you should do it yourself,” prefer to prepare their own.

Among the qualities to be sought, the following seem to be the most important. The ground should be impervious to the acid, in order to protect those parts of the plate which are not intended to be bitten. It should cling to the copper with sufficient tenacity to prevent the mordant finding its way between them, at the same time that it should be so easily removable by the etching-needle as to offer the least possible resistance to the free play of the artist’s hand. If too hard, it will chip from the copper, and flake off as the needle passes through it — a ragged line being the result ; if too soft, it will be liable to accidental injury which will lead to “ foul biting.” A soft ground, moreover, sometimes shows a tendency to be torn from the plate by the needle. And in hot weather it will sometimes cling to the needle-point, which thus becomes clogged with the ground, and incapable of making any but a broad and clumsy line, a state of things which involves a frequent wiping of the needle.

The happy mean indicated by these varied requirements is realised by a judicious combination of certain hard and soft elements of which the ground is composed : the soft element generally adopted being pure white wax, and the hard elements such substances as asphaltum, resin, gum mastic, black pitch, Burgundy pitch, Japan varnish, &c. And it may be observed that the elements should be com¬ bined in different proportions, as the ground is required for use in hot or cold weather : a ground which would be too hard for use in cold weather giving satisfactory results when the temperature is high.

THE ETCHING GROUND.

Another point which should be considered in connection with the mordant to be used, is the colour of the ground. If the hydrochloric mordant, which darkens the bitten sur¬ face of the copper, be adopted, it will be found convenient to work with a somewhat pale ground, in contrast with which the darkened lines of the etching will be clearly discernible. When the mordant used is such as leaves the bitten lines pale, which is the case with nitric acid, a dark ground may be preferable.

In the published formulae for the preparation of etching ground it is usual to find several of the above-mentioned “ hard ” elements combined together, with a view of securing the double character of hardness and adhesiveness. It appeared to the writer that, if a single substance could be found affording both of these qualities, it would be preferable, on the score of simplicity, to use it in exclusion of any other. This desideratum he found to be supplied by asphaltum, and after many experiments he was led to adopt a simple mixture of asphaltum and wax. This he has used for many years, and has found it to be impervious to the acid, and quite free from objection in other respects. In a thin film it gives a light brown colour, sufficiently dark, without being smoked, to afford contrast to the bright lines where the copper is exposed by the needle, and thus to enable the artist to see the line as he draws it; and, on the other hand, pale enough to allow the lines when darkened by the hydrochloric mordant to be clearly seen.

The proportion which the wax should bear to the other ingredients of the ground varies much in the several formulae put forward by writers upon etching. In Bosse’s ground — one which can with safety be recommended — the proportions by weight are as follows : — Wax, ten parts ; gum mastic, six parts ; asphaltum, three parts. The materials are combined by melting in a glazed earthenware pipkin ; the wax being first melted, and constantly stirred with a glass rod, while the asphaltum and gum mastic are gradually added ; and the

PRACTICAL NOTES ON ETCHING.

whole, when thoroughly melted and mixed, may be either poured into warm water, and made up into balls for use, or converted into “ etching paste ” by the addition of oil of lavender.

When asphaltum forms the only “ hard” element employed, it seems that the proportion of wax should be much less than that above indicated; and especially is this the case when the practice is adopted of dissolving the ground, and applying it to the plate in a liquid form. The writer has found that an excess of wax not only occasions difficulty in filtering, but sometimes altogether prevents the ground drying.

For liquid ground it will probably be found most convenient to keep the materials in separate solutions, and to mix them in the necessary proportions when required for use. To prepare the solution of asphaltum, the substance should be pulverized, and tied up firmly in one or two thicknesses of very close fine muslin, and so placed in chloroform in a wide¬ mouthed bottle. The soluble portions of the asphaltum will pass freely through the muslin, while the impurities will be left behind, and the solution may then be decanted into its proper stock bottle for use. The wax solution should be also prepared in a similar manner, the wax being previously scraped into thin shreds. The solutions should be sufficiently thin to flow easily, and they should be combined in propor¬ tions of one part by volume of the wax to five parts of the asphaltum. In hot weather the proportion of the wax may be much smaller, and in intense heat it may be sometimes found desirable to add a small quantity of gum mastic, which may also be kept in solution, prepared in the same manner as that of asphaltum. Especially is this the case when the nitric or nitrous acid mordant is used, the effervescence attending which has a tendency to disturb the ground at the edges of the lines, from which a still mordant is comparatively free.

LAYING THE GROUND.

IV. — Laying the Ground.

There are three methods in use for applying the etching ground to the copper, all of which it may be well to describe, as each is useful under special circumstances.

In the first, which until recently was that usually adopted, the plate is heated sufficiently to melt the ground without burning, or causing it to boil. For this purpose it may be held in a hand-vice over a gas-jet — its face being protected from the roughness of the vice by a cushion of soft paper. To insure the proper degree of heat is of the highest import¬ ance. If the ground becomes burnt it is no longer of use, and, should the heat of the copper be such as to cause it even to smoke, the ground should be at once wiped off and a fresh ground laid.

Should the etcher contemplate proving his plates himself, which he is strongly recommended to do, he will have to furnish himself, among other printing apparatus, with a heat¬ ing plate, and this he will find of the greatest convenience for laying the ground, especially upon plates of large dimension. It consists of a large iron plate, of about half an inch in thickness, the space beneath which is enclosed with sheet iron, and heated with gas-jets, or a spirit-lamp. By this means the heat can be easily regulated, and an even tempera¬ ture maintained for any length of time. And it may be observed that for printing purposes the iron plate should be considerably larger than the copper, and it should be heated by more than one jet, placed sufficiently far apart to admit of different portions of the iron being kept at different degrees of temperature. A convenient heating table of cast iron (Fig. i) is manufactured by Messrs. Hughes and Kimber, of Fetter Lane.

Another plan for heating the copper plate is to have a flat rectangular box of copper filled with water, which is kept at the proper temperature by a gas-stove or spirit-lamp.

PRACTICAL NOTES ON ETCHING .

Over the whole surface of the copper plate thus heated, the etching ground, previously made up into a small ball, and wrapped in a piece of thin porous silk, is rubbed, and, being melted by contact with the copper, passes freely through the silk. It is then equalised and distributed over the plate in a thin, even layer by means of a silk or leather dabber.

The dabber should be flat with rounded edges, smooth, soft, and elastic ; and may be made as follows. A circular disc of thick cardboard should be prepared, having a diameter of about three inches, three or four thicknesses of the softest cotton-wool of the same size, some horse-hair, and a piece of strong, smooth silk about eight inches square* The silk being spread out, the cotton-wool is first laid upon it, then the horse-hair in an even layer, and last of all the cardboard disc. The silk is then run round with a needle and strong thread, at a distance of about an inch outside the edge of the cardboard, and drawn up so as to enclose the whole, and, the edges being brought together and fastened off to form the handle, the dabber is complete.

A piece of kid leather is sometimes substituted for the silk. Both materials present a certain roughness of surface, due, in the one case, to the texture of the silk, and in the other, to the minute papillae from which the animal's hairs have sprung; and the utmost care must be taken that in spreading the ground the copper is thoroughly covered, and the occurrence of “ pinholes” avoided.

LAYING THE GROUND .

i

Another mode of applying the ground is by means of a roller (Fig. 2) ; an implement introduced in Paris, originally for the purpose of laying the ground for rebiting, but which is equally serviceable in laying it in the first instance. It consists of a wooden roller about two inches in diameter and five inches in length, covered with leather, and resembles in miniature an ordinary garden roller.* The ground is applied in the form of a very soft paste — almost liquid — made by adding a suffi¬ cient quantity of oil of lavender to the other ingredients when

Fig. 2.

in their melted state ; and it is spread, in the first instance, upon a clean copper plate, and the roller passed and repassed over it until every part of the latter’s surface is evenly charged with the ground. The roller is then transferred to the plate which it is proposed to coat, and moved backwards and for¬ wards upon it until the surface of the copper is entirely covered with an even film. The volatile oil of lavender is then driven off by the application of a moderate degree of

* These rollers are now made of gelatine, which affords a surface of more perfect uniformity than the leather.

PRACTICAL NOTES ON ETCHING.

heat to the back of the plate, and the ground left in a firm state.

In laying the ground it is very essential to avoid, as far as possible, the admixture of dust, the particles of which would cause weak places through which the acid might find its way. Unfortunately, in either of the above processes, minute par¬ ticles may be present without their presence being disclosed ; and this fact, coupled with the great difficulty of finding an atmosphere free from dust, inclines the writer to prefer the process of applying the ground in the form of solution. By this method “ pinholes ” are altogether avoided. Dust, although it may be almost obviated by the apparatus pre¬ sently to be described, cannot be absolutely eliminated, but it either floats off on the surface of the solution, as it is poured back from the plate into the bottle, or, failing this, it effectually declares its presence by a certain amount of disturbance which it causes in the uniformity of the film ; and it can then, if necessary, be stopped out before the plate is bitten.

The writer has found chloroform to be the best solvent for the ground, but the solution should be passed two or three times through filtering paper before it is used. It is desirable to use plenty of the solvent, and to have the ground in a very fluid state ; and care should be taken to have the chloroform perfectly free from globules of water.

In applying the ground, the plate, if small, may be held in the hand, while the solution is poured over it from the bottle — as collodion is poured over the glass by a photographer. It should then be tilted in order to carry the solution into every corner, and the excess of solution poured back into the bottle from the last corner visited.

In the case of large plates the following difficulties present themselves. Owing to the extent of the surface, the chloro¬ form, being exceedingly volatile, evaporates, and the solution dries over some portions of the plate before others have been covered — the result of which is a film of uneven thickness. The dust also, of which there is always much floating in the

LAYING THE GROUND.

1 3 atmosphere, has time to settle upon the plate, and becomes a source of considerable annoyance. To obviate both of these difficulties the following plan may be found useful. The apparatus (Fig. 3) required consists of a drawing-board and a light wooden frame, rather smaller than the board, but larger than the plate in¬ tended to be operated upon, and having a groove round its inside, after the manner of a school-boy's slate, to receive a sheet of glass. The groove should be so placed that, when the frame is laid upon the drawing-board, the glass should be dis¬ tant from its surface about a quarter of an inch ; and along one side of the frame the wood should be cut away from the under-side of the glass, and the latter prolonged to form a handle for raising the frame. A glass tube (Fig. 4) is also required about a foot long, closed at one end, but having the other end spread open, and fitted to receive a cork. The tube is for the purpose of holding the chloroform solution, and it should be bent to a right angle at a distance of about an inch and a half from its open end. The glazed frame being laid upon the drawing-board with its “ handle ” side projecting about a couple of inches

PRACTICAL NOTES ON ETCHING.

beyond the edge of the board, the plate is introduced between them, and so placed that one of its corners also projects beyond the board to a distance of about an inch. The apparatus should then be placed upon some circular support — such as the bottom of a large basin turned upside down — and, the glazed frame being slightly raised, the tube filled with the chloroform solution is introduced, and a sufficient quantity of the solution poured on the centre of the plate — an operation which is much facilitated by the bend in the tube above referred to. The tube is now withdrawn, and the frame replaced, and the drawing-board, with the plate and frame upon it, tilted in every direction upon its circular base, so that the solution may be carried over every portion of the plate. It will be found that, owing to the extreme thinness of the stratum of air in con¬ tact with the solution, evaporation takes place so slowly that there is ample time for the plate to be successfully covered long before the solution dries.

In case the latter should manifest any hesitation in flowing over the plate, it is well to have a long piece of wire at hand with which the operation can be forwarded. When the plate is coated, the excess of the solution can be returned to the tube from the corner which was left projecting over the edge of the board.

After the plate has been coated with the solution, twentyfour hours should be allowed to elapse before it is submitted to the action of the mordant. The chloroform, it is true, soon evaporates, and the ground becomes in a certain sense dry, but it remains for some time tender, and would in that state afford a very imperfect protection to the plate.

V. — Colouring the Ground.

Among the difficulties which beset the etcher’s path, there is one which appears to have exercised his mind not a little —

COLOURING THE GROUND.

1 5 that of not being able to see clearly his work upon the copper while it is being executed, and several expedients have been devised for the purpose of overcoming this. Foremost among them is the plan of smoking the ground. All that is essential is a sufficient contrast between the etched line and the ground upon which it is traced, and it is difficult to imagine any contrast more complete than is afforded between the bright copper of the lines exposed by the needle, and the dead blackened surface of a smoked ground. It is true that the effect of the picture, as regards light and shadow, is the con¬ verse of that which is presented by the proof when the plate comes to be printed, — the black lines of the proof being represented by burnished copper, and the white paper by the blackened ground. But this is of little moment. All that the artist really requires is the power of seeing his work as he does it, and this the smoke upon the plate enables him perfectly to do.

The best way of smoking a plate is to pass it, face down¬ wards, across the broad and steady flame which issues from a “ bat’s-wing ” gas-burner. Where the convenience of gas does not exist, the old plan of twisting together several pieces of thin taper into a sort of flambeau may be adopted. In either case, great care must be taken that the ground does not become burnt.

It is not only while working with the needle, however, that the artist requires to see his lines. This is equally indispen¬ sable during the process of biting, and it is obvious that, if the ground be darkened, it will be necessary to use a mordant which will keep the lines bright, or at least pale in colour. This the nitric acid mordant does. The hydrochloric mor¬ dant, on the other hand, darkens the lines to such a degree that they are quite indistinguishable from the smoked ground, and, when that is used, the ground must be kept pale. On this principle, and in order to obtain the utmost degree of contrast, and at the same time to insure that the lines of the etching shall appear dark upon a white surface, Mr. Hamerton i6