AT one time a great many glass transparencies were used for advertising or display purposes, and many are still being used because they can be easily illuminated by small electric bulbs, making attractive advertisements at night. A transparency in a window can be kept illuminated all night long with the balance of the window dark; and the expense is small. The picture is also more attractive.

Such transparencies are rather expensive, especially in large sizes but we find that translucent prints are now being used in many places. More of these prints could be sold if people who use pictures for display purposes knew that prints could be made translucent.

There is a decided advantage in the use of translucent prints because they can be viewed in the daytime the same as ordinary prints and illuminated at night, while a glass transparency must be illuminated at all times. Prints also cost considerably less and can be made in large sizes, whereas glass transparencies are limited as to size.

We have made a number of laboratory tests to determine the best method of making prints translucent and find that while mineral oil, castor oil, linseed oil, melted paraffin, wax, or Canada balsam may be used, the best results are secured with one of the heavy white mineral oils that are now in common use and that may be secured at any drug store.

Our tests showed that the papers best suited for making these paper transparencies were Artura Carbon Black, Iris E Smooth, Royal Bromide and Standard B Bromide.

The transparency is determined by the nature of the paper, its thickness and the nature of the baryta coating. Some papers that seemed to have a very fine grain before treatment with the oil, developed very high graininess after treatment owing to an uneven rate of absorption of the oil. In some cases this disappeared with age but in others it did not. Damp papers invariably produced bad graininess so it is essential that all papers be thoroughly dried before treating with the oil.

The quality of the print required for a transparency is determined by the amount of light transmitted by the treated paper, the contrastiness desired and the method of viewing - whether it is to be used as a transparency or as both a transparent and an ordinary photograph to be viewed by daylight.

With a heavy opaque paper stock it is necessary to develop as dense a deposit of silver in the shadows as possible to produce good contrast in the transparency. The print should be fully exposed and fully developed.

From An Eastman Portrait Film Negative By Thos. H. Ince Studios Culver City, Cal.

From An Eastman Portrait Film Negative By Thos. H. Ince Studios Culver City, Cal.

With a thinner and more transparent paper the shadow density may be less and the print will appear more like a normal print when viewed by reflected daylight.

The intensity of the illumination for transparent prints can only be determined by trial. Experiment with an illuminated portrait in your own display window, or in the studio to determine how much light is necessary to give the best effect.

Color effects may be secured by tinting the entire print with a colored dye or by hand coloring the print with Velox Water Colors before applying the oil. Prints which we oiled over two years ago have not lost their trans-lucency and have not become brittle, while their graininess has greatly decreased with age.

The method of oiling is simple. First, dry the print thoroughly, then brush the oil over the back of the print and allow it to stand for one hour. Then repeat the oiling, allow the print to stand over night and remove the excess of oil with a cloth next morning. It is not necessary to apply the oil to the gelatine side of the print because the gelatine is impermeable to oil.

If, for any reason, it is desired to attach the oiled print to a glass, the following formula for an adhesive will be found satisfactory:

Gelatine. ..... 125 grains

Sugar........ 30 grains

Water........ 3 1/2 ounces

First allow the gelatine to swell in the water, pour off the surplus water and heat the gelatine until it melts, add the sugar and make up the volume to 3 1/2 ounces. Coat the print and the glass with the hot adhesive, taking care to avoid air bubbles and then squeegee into contact.

In illuminating large paper transparencies it is better to use a number of small lamps rather than one large one, as the illumination will be more even.

With these simple instructions and a little experimenting anyone can make good paper transparencies. And there should be no difficulty in selling such prints for display purposes.

Photographers in ever increasing numbers are using Eastman Portrait Film, not because they have been told of its superior qualities, but because it has enabled them to make better negatives.

From An Eastman Portrait Film Negative By Thos. H. Ince Studios Culver City, Cal.

From An Eastman Portrait Film Negative By Thos. H. Ince Studios Culver City, Cal.