THE PHOTOGRAPHIC NEWS, Vol. V, No 168, November 22, 1861, p.551
Read at a meeting of the south London Photographic Society, on Thursday November 14. 1861
THERE are few things which contribute more to the general perfection of result in a picture than the mode in which it is mounted; ; and. as most photographers know, much of the permanency depends upon the adhesive material used in mounting. As but comparatively little attention has been given to this subject, I propose very briefly to devote a few words to the general question.
The first point to be considered will necessarily be that of trimming and shaping the print preparatory to mounting. in deciding the shape to which a print should be cut, whether rectangular or circular, oval, cushion, or dome, three considerations will weigh: first as to how much of the print makes a good composition ; second, as to whether the corners, &c., are perfect, and third, the general contour and character of the lives in the picture. No specific directions can be given regarding the first point ; nothing but good taste and a knowledge of the laws of composition can guide the photographer in determining how the picture will gain by the retention or exclusion of an inch, more or less, of the subject in his negative. His technical taste will, however, readily guide him to the rejection of dark or ill-defined corners, unless indeed they aid the composition in some degree. 1 remember some one exclaiming, when examining some of Wilson's instantaneous sea pieces, recently exhibited as single pictures about 4½ by 3½ in each one of which the dark corner produced by loss of illumination and definition at the edge of the lens was present, "What a pity Wilson did not vignette these prints, or cut them oval or circular, so as to get rid of these dark corners!" "That," replied another gentleman, who knew Wilson, "would have entirely frustrated the intention in leaving them, which is to force the lights, and by contrast give brilliancy to the prints, as they are from very thin negatives." This is an expedient, however, which should rarely be used, and then sparingly. But it illustrates that there are occasions when power may he added to the composition from the retention of a dark corner imperfectly illuminated or ill-defined.
The best shape for the print will often be governed by the prevailing lines in the picture, and especially by the general character of the outline. Where a number of parallel lines, vertical or horizontal, prevail in the subject, an oval or circular shape will often materially help the picture, and prevent the formation of angles, which must become striking if the rectangular shape be adopted. On the other hand when tile principal lines fall in curves, the rectangular shape will be most suitable. In no case, however, is a perfect square desirable. The oblong form should in all cases be chosen : whether the greatest length should be vertical or horizontal, will be governed entirely by the subject.
It is never desirable in shaping the print, to follow the outline, or principal lines of the picture. If the picture be vignetted, it will rarely look well cut to an oval, circle, or dome; the corners should in almost all such cases be left square. The object should be to secure harmonious variety, and by the shape of the print to give the utmost value to graceful lines, or to distract attention from awkward forms. Another purpose may be sometimes gained by the shape of the print. It sometimes happens, especially in architectural subjects, that in obtaining a view of certain objects, it is immediately surrounded by others of less interest, which cannot be entirely removed without spoiling the picture. Where vignetting cannot be, or has not been, used to partially ignore these intruding elements, then the circular or oval form may be adopted with advantage, which by cutting away portions of the objects not required, at once gives importance to the principal figure left alone in its integrity. These, of course, are but general hints, not absolute rules. I may here remark that except where the exigencies of the photograph imperatively demand it, on account of dark corners, &c., I think that the shape styled by photographers the "cushion" shape, should generally be avoided as meaningless and inelegant. In most cases where it is used, the perfect rectangular shape would be much better. Where the corners are rounded, however, care should be taken to avoid a sweep which leaves it uncertain whether it is a flattened circle, an imperfect oval, or a cushion.
I may here add also one word more on the cutting cut of card pictures. These are, of course, always best left rectangular. But it is an important point to remember that the due proportions of stature are chiefly indicated by the amount of space at the top and bottom of the figure. The size of the picture is generally from three inches and five-eighths to three inches and three quarters long. As a general principle, the amount of background above the head should be from half-an-inch to three-quarters of an inch, and the space below the feet, not more than a quarter of an inch. The exact amount will vary, of course, with the stature of the figure, but these remarks apply to a middle height. I may add also that it is a good thing to adopt a standard scale of proportion in taking such portraits, in order to give the pictures the value of suggesting truth in this respect. About half-an-inch for each foot in height would be found a good approximate scale for standing figures.
The best mode of shaping is to proceed as follows: If the prints have been rolled up, and are, therefore, inclined to curl, roll them the reverse way on to a roller and leave them for a few minutes, at the end of which time they will lie straight. A thick piece of plate-glass cut to the required size and shape is the best guide, as it enables the manipulator to see exactly the position and amount of picture included. I may here describe a very good contrivance described to me a day or two ago by Mr. Samuel Fry, which he had made for cutting out the card portraits. It consists of a plate of copper with an aperture the size and shape of the photograph. At each corner of the aperture there is a slight slit, proceeding, both vertically and horizontally, a little into the copper, so that in cutting, the knife passing into the slit, cuts the corner of the print clean, which it would be somewhat difficult to do if the knife could only just pass up to the corner. A sharp knife or old razor may be used to cut with and a piece of glass, or a piece of smoothly planed lime-tree, to cut upon. The latter is most valuable, as it does not so readily null the edge of the knife ; and unlike other woods, its grain and texture are sufficiently homogeneous to allow the knife to pass without the vibration which gives a ragged edge. The utmost neatness and skill in getting a clean cut edge, free from jaggedness is imperative.
The proportion of margin is another subject on which the educated will be the best general guide ; but upon which a few hints may he useful. Few things contribute more to give value to a print than a respectable margin ; it is nevertheless by no means an uncommon thing to see very fine pictures spoiled by shabby mounting. Nothing would be more difficult than to lay down any absolute rule on such a subject; but a very fair approximation to a rule may be obtained by deciding that the margin on the sides should never be less than one-third of the breadth of the print. and on the ends, not less than one-third the length. With small prints a margin of not less than two-thirds of the length and breadth is desirable for the best effect.
Under some circumstances the proportion of half the breadth for the side margins, and half the length for the ends will give a good result. But I have heard this principle objected to by persons of taste, as tending to formality and stiffness ; it being urged that all proportions consisting of parts of even numbers tend to that formality. I have heard some attempt to establish a principle based on the analogies of musical science ; but I fear that it would be difficult and unsafe to lay down definite rules on a subject which must largely be governed by feeling and educated taste.
A very excellent effect is produced by a narrow margin of india-paper immediately around the print; or of what is now commonly used as a substitute, a tint produced on the mounting board by lithography, in imitation of india-paper. This tint often gives great value to the whites of the photograph, and general relief to the tone of the picture. in some eases a good effect is produced by leaving a somewhat larger margin at the bottom than the top. In card portraits, for instance, it is better to leave about half-an-inch at the bottom, and about one-eighth of an inch all round. In all cases it is desirable to avoid intersecting corners; that is a line drawn diagonally through the mount, should not intersect the corners, first of the india-paper tint, and then of the print. Where the corners thus intersect, the effect is inevitably formal.
The next point for consideration is the best adhesive material, and the best method of using it. A great variety of materials have been recommended for this purpose, amongst which gum, dextrine, pastes of various kinds, glue, india-rubber, &c., have been chiefly used, and each has had its advocates. I do not propose to enter into any extended discussion of their respective merits, but just to offer one or two remarks on the subject.
The qualities necessary in any such material are that it should be easy to prepare, easy to use, efficient when used, and free from deleterious effect upon the photograph. Gum has the disadvantage, if thin, of sinking into the paper and showing on the face of the picture. It has moreover the tendency to rapidly turn acid, and if used in this state it injures the photograph. Making it with boiling water reduces the tendency to acidity or decomposition ; and if made thus and used sufficiently thick, I think it may be used without disadvantage. Dextrine I have not used, but I believe there is no positive objection to its use. Of the various kinds of paste that made of starch is preferable, and if used fresh, is, 1 believe, perfectly safe. I prefer the patent starch, in powder, and without the blue tint for my own use. I may here describe a simple and efficient method of making it. I take a teaspoonful of the powder, and put it into a common marmalade jar, this is then mixed with the smallest quantity of water which will make it into a thick paste. When it is rubbed perfectly smooth, boiling water is poured on it, the whole being rapidly stirred. Sufficient boiling water is used to make a thick transparent jelly, and one good teaspoonful of the powder will make a jarful of paste. This will keep good a few days in summer, and longer in winter. It is easily made, easily used, efficient, and will not, if used properly injure the photograph.
Glue, gelatine, isinglass, &c.., are used by some. Of these I think good Scotch or Russian glue will lie found best. This for persons only mounting occasionally will be found troublesome to prepare and use, but it is very efficient, and I believe safe.
I may here refer with advantage to some experiments undertaken, and detailed to the Photographic Society of Scotland a few years ago, by Mr. Colin Sinclair. His object was to determine the effect upon the permanency of the print exercised by the various materials used for mounting. I will read one or two extracts from his report.
"I prepared a small quantity of each of the substances already named ( starch, albumen, isinglass, and gum-arabic), in separate dishes, and selected two of Mr. Tunney's photographs, one of china of the brown tint on albumen. sized paper, the other or the black tint on plain paper. I cut each of the two prints into five pieces, the fifth piece being laid aside for future comparison and then distributed the four pieces of each picture over the four dishes containing the different materials, so that there were two pieces completely immersed in each dish. They were kept there for one month.
"I would have allowed them to remain longer in this state, but the pieces because so fragile, that I could hardly remove them from the liquids in which they were immersed. After cleaning the pieces, I mounted them along with the fifth piece, so as to show time relative effects on each, and I now lay the mounted results before you.
"It will be observed that the brown photograph on albumenized paper has suffered the most, especially the piece that was immersed amongst the albumen,--it has given way very much; the pieces that were amongst the isinglass and the starch are slightly affected; that which was in the gum is the least changed of any, while the black picture on plain paper come out of all the four different substances much the same as it was."
Conceiving that it might be more satisfactory still to test the keeping qualities of pictures mounted with these materials, he took two other photographs and cut them each into five pieces, mounting four of the pieces, each with a different material, and keeping one piece unmounted for comparison. These mounted pieces were theme placed in a damp cellar, where all the conditions generally considered averse to photographs were present in an exalted degree, and kept there for twelve months. At the end of that time they were submitted to the Scottish Society. I will read a brief extract from the report. Mr. Sinclair says
"The fifth piece, lying on each cardboard in juxtaposition with the mounted pieces of the pictures, shows the original colour, from which it will he observed that the whole tone is somewhat changed, hut still indicating the superiority of the starch and the gum-arabic for mounting photographs,
"In the first experiment--that of steeping--the plain paper photograph, of a black colour, was less changed than that on the albumenized paper but the result is reversed in the two mounted pictures--the one on plain paper, of a brown colour, being more injured than the others. This may be partly accounted for by the black-coloured picture having been a stronger print. The four photographs thus tested had been well washed with warm water, otherwise they could not have withstood the treatment so well as they have done, as is evidenced by the third picture in the hands of the members, which from its tone did not appear to have got justice to the washing, and was only about a fourth of the time in the cellar along with the others.
"As regards convenience of application, I prefer starch when mountings photographs, as it can be used with greater facility and cleanliness than gum-arabic, whirls, however, is very useful for an occasional picture, as it is inconvenient and not worth while making fresh starch every time an amateur requires to mount a few pictures."
From these experiments it would appear that Mr. Sinclair found starch and gum the most conducive to the well-being of the photograph. My own predilection is in favour of starch, simply because I have found it so easy to prepare, and because as it will not keep, it must be prepared fresh; there is not, therefore, the same temptation to use it when unfit, which there is when a bottle of gum it kept for occasional use. I have heard the objection used to starch that it might generate acid even after the picture is mounted. I have no fear, however, that the dry particles of starch, by which nay prints are made to adhere to the mounting-board, will produce me either sugar, alcohol, or acetic acid. There is, however, another consideration which, under some circumstances, will influence the decision as to the adhesive material to be selected. There are two sources of trouble in mounting to which I have not yet adverted--curling and cockling. The cause of both these troubles is this the print on being coated with paste or gums becomes saturated with moisture and expands. it is mounted on the board in this expanded condition and as the moisture evaporates it contracts again to its original size, or even less. and draws with it the board on which it is mounted. Where there is a margin of hoard all round the print, "cockling. or uneven contraction often results. It will readily he seen that those substances which contain the most moisture, such as gum or starch, will produce those evils in the greatest degree. Where the pictures are mounted with a margin, this is an important consideration, and for this purpose it will be found that glue causes the least trouble. In using it the print does not expand much, and there is consequently little contraction. The curling, &c., may also be obviated by sponging the mount before laying down the print, so that both shall be equally expanded. The plan described sonic time ago by Mr. Stuart, of Glasgow, is also a good one for preventing this defect. Each print is covered with starch paste before trimming, and then dried. When they are to be mounted they are trimmed and shaped, the hoard, slightly wet, and the print placed upon it in position. The two are then passed through a lithographic press, which brings them into firm contract and completes the operation.
I may here mention a little hint which will be found of great service to those who have large numbers of card pictures to mount. When the prints are very stiff and dry much, it is difficult to cover them with the starch, without their curling up, and smearing the surface. To prevent this take a clean sponge and damp a few dozen before pasting them, they will then lie perfectly flat, and cause no difficulty. Although this involves two operations it will be found an actual saving of time.
I will, in conclusion, just refer to the use of india-rubber paste. This is scarcely suitable for general mounting purposes but is invaluable for fixing prints in albums or scrapbooks. A slight touch of the paste at each corner attaches the print to its place in the scrap-book, and keeps it perfectly flat, without the slightest contraction, or "cockling." The paste is made by dissolving shreds of india-rubber in chloroform or benzole.
I now invite inspection of a variety of specimens I have brought to illustrate my remarks, and add, that the bulk of them--nil those with the India paper tint--were mounted by Mr. Fox, of Little Britain, whose neatness, skill, and taste, in mounting generally, I can commend in the highest terms.
I have not said anything here of hot-pressing or rolling, but I may conclude by observing, that I consider it indispensable to perfect results.