226. As a rule, backgrounds are made to be upon a frame with their whole surface equidistant from the camera. Another form, recommended by Mons. Adam Salomon, the renowned master photo - artist and sculptor, of Paris, by the use of which gradation was secured, known as the "alcove" background, came into use a few years ago, but for some reason or other soon fell into disuse. Such was the fate also of Mr.Kurtzs' very ingenious cone - shaped background. Both had merits, hut the were cumbersome, and seemed to be ahead of the intelligence possessed by the fraternity at the time. Again, pretty much the same effects could be obtained, by gradating the plain background in various ways.

The effect of gradation on a background in producing relief in a portrait often seems to be overlooked by photographers. No one, on looking over a collection of photographs, vignette heads, medallions, etc., can fail to notice the even and unbroken tint of the backgrounds generally.

The following plan will, in great measure, supply what is wanted without extra time or trouble: A square background (about four feet is a convenient size), on a frame with a cross piece at the back, in the centre of which is a hole to allow the horizontal rod of the rest to pass. It will be seen that when the rest is placed against the head of the sitter the face appears in the centre of the square. There will be found no difficulty in painting this small background with a gradation from dark on one edge to light at the other. Lampblack and whiting, with a little size, answers capitally. This can be turned round any way; light at the top, shading into dark below, or vice versa; or a diagonal gradation to suit circumstances or taste. It is astonishing the different effects produced by turning this background round. Sometimes the effect may be improved by shielding part of the light from the background with a blind or curtain. From the fact of this background being so close to the head of the sitter, a bold cast shadow can be obtained from the head or shoulders, which is very effective. - H. Gillo.

226. Now as to the alcove background, a few brief hints on the construction of the combination may be useful. The formation of the curved background itself is the chief consideration.Mine consists, first, of two curved pieces of wood to form the framework. These art - placed one for the bottom and one for the top, at the proper distance apart, and a series of thin, narrow planks, not more than three or four inches wide, are fastened to the curved pieces of wood, the planks being fastened to each other by means of a groove and tongue.| the ground depends upon the individual taste of the maker, hut is again influenced by the alternative whether the picture is destined to bo printed in full, or only as vignette. In most cases one side is kept darker than the other, and usually the middle appears lighter than the margin. - Dr. Edward Liesegang.

When complete, the little angles or irregularities in the curve are taken off with a plane. Probably, if well-made laths, something like those used in Venetian blinds, were employed, a more perfect and regular curve might be more easily obtained. In such case, the general framework would probably require to be a little more firm or rigid. I found it desirable to increase the rigidity - seeing that the arrangement is often wheeled rapidly about - by means of a binding of iron running round the top and bottom of the curve. The background may, of course, be painted, or sanded, or treated in any manner to suit the taste. - Adam Salomon.

227. As much artistic taste, a thorough knowledge of color, the effects of light and shade from various causes and sources, and the principles which govern them all, are necessary to the production of photographic backgrounds, and since America is favored with such renowned background painters, it is hardly recommended that photographers attempt

227. The backgrounds you can do by sizing your cloth with glue-size, with a little alum in it, but do not use this size to mix with your color, glue-size without alum will work the best. First, coat in your groundwork, then use your color weaker with glue-size, and all subsequent additions, until you have accomplished your purpose. It is fully as well to draw in your designs with chalk before taking in hand the color, if it is not handy for you to work without the chalk marks. The colors best to use are raw umber, ivory-black, and whiting, mixed to your fancy with glue-size. - M. H. Albee.

The influence of the background upon the quality of the portrait is enormous. The background serves to bring out the figure strong and bold, and ought, therefore, never to suppress the same. If the background bears a drawing, the details of the latter must only be faintly indicated, never strongly marked out. In order not to act too much itself, the background must be without lustre. Although good and suitable backgrounds are met with in the market at present, it may yet be of advantage to know a very simple way to make, one's self, without much trouble, an effective background for certain special purposes. As a basis, common unbleached sheeting serves usually; the same is wet and stretched smoothly upon a wooden frame, coated evenly with a thin paste, or with solution of dextrin, and left to dry. The color is prepared by mixing thoroughly ground dextrin with lamp-black and umber, and is placed dry with a linen pad upon the sheeting. After the desired effect has been obtained, the reverse part of the sheet is moistened with a sponge, which has been moistened in very weakly acidulated water, and thereby the color becomes fixed. If still greater durability should be desired, the flat-lying, quite-dry background is coated with a solution of thirty grains dammar rosin in one pound benzine; this varnish dries up dull. In place of the mixture of dextrin and umber, the following may be used to advantage. Mix in the proportion of five hundred grammes ivory-black and umber with two and a half kilogrammes boiling water, to which two hundred and fifty grammes good glue are added, which has been soaked previously twelve hours in cold water. The whole is caused to evaporate until dry, when the remaining coloring matter is ground fine. This dry color is laid on with a cotton rag upon the stretched dry sheet. It is easy to produce any desired gradations, and care is to be taken to begin painting first on that side which is to be the darker one. According to desire and necessity, white color may be admixed. Clouds are very easily painted in this way. The treatment of the sheeting before and after painting is the same as the one indicated above.