The subject of paper negatives is discussed within the book 'Amateur Photography' by Anthony Johnstone, first published 1935, 7th edition (revised) 1951 (copyright acknowledged). Mr Johnstone writes:

"The first photographic negatives ever produced were made on sensitised paper. Now (1951), after a long period during which glass and various types of cellulose nitrate and cellulose acetate - generally referred to as 'celluloid' - have been used almost exclusively as the base for the negative, paper is again being used.

Paper negatives have some definite advantages. Paper is considerably cheaper than either glass or 'celluloid'; it is easier to coat with sensitive emulsion; it is easy to cut to any size desired, and it is the easiest of all materials on which to work if it is desired to spot, retouch, or control by shading.

'The problem of grain in printing'
The defect of paper as a base for negatives, that led to the almost universal use of glass and 'celluloid', was its grain. Even the finest and thinnest papers show a mesh of grain if held up to a strong light, and when a paper negative is printed by transmitted light, it is practically impossible entirely to avoid reproducing this grain in the print.

Until recently the usual method of those who wished to use paper as a negative base was to choose a paper with the least pronounced grain and to reduce the effect of the grain by oiling the paper, thereby also increasing its transparency and reducing the time necessary when printing through it. This reduced rather than eliminated the inherent defects, and oiling brought its own problems and troubles with it.

'Printing paper negatives by reflected light'
Now (1951 remember !), high-power gas-filled electric lamps have made possible the printing of negative images by reflected, instead of transmitted light, and the grain of the paper becomes a matter of no importance. By this method paper negatives have become suitable for a wide range of photographic purposes. They are now used extensively - notably for inexpensive professional portraiture and for other types of work in which their low cost is especially advantageous.

'Reflected-light printer'
Alongside is an illustration of a reflected light printer for paper negatives. The size of the print can be varied by adjusting the negative-to-lens and lens-to-sensitive paper distances to give a sharp projected image. The quality of prints produced by this method, when a suitable negative is used, is very little below that possible when film or glass plate negatives are printed by transmitted light."

Digital technology now supplies the answer to printing paper negatives. In this respect I'm indebted to Mr Peter Monaghan who related his successful printing of some old Gratispool paper negatives by digitally scanning them, reversing the images and then using an inkjet to produce the final results.

The term 'Contact Prints' refers to prints made by exposing to light a celluloid or glass based (transparent) negative held in close contact with light sensitive printing paper. To firmly hold the negative and printing paper together, the two are usually clamped against a piece of clear glass inside a contact printing frame.

Silver chloride based Contact Paper was sold specifically for the contact printing process (previously, contact printing was done using PoP, standing for Printing-out Paper, which darkened without the need for development). Contact Paper was slower (less sensitive to light) than the silver bromide paper used for making enlargements. It's relative insensitivity was no disadvantage because there was much more intense light transmission directly through the celluloid negative, compared to projection printing using an enlarger. Hence, contact paper could be made relatively light insensitive and thus could be conveniently handled by quite a bright, yellow, safelight and didn't require a darkroom; amateur hobbyists could produce contact prints at home using the dimmed area of a normal room lit by artificial light. Before the common usage of electric lighting, contact paper was known as Gaslight Paper, as its insensitivity to the yellow light coming from a 'Town's Gas' mantle meant it could be used in the shaded corner of a living room during the evening, before television was a common means of entertainment.

These pictures show a Johnsons of Hendon 'Mains Contact Printer', which was an upmarket arrangement of the simple contact printing frame. It was priced at £1.8s.6d (£1.43p) and was sold from around 1956. The "Mains Contact Printer" provided an integral yellow safelight (by virtue of its 15watt mains bulb shining through the printer's yellow plastic walls from within) and a glass platen onto which first the negative, and then the printing paper, could be safely clamped using the top lid. Once in place, an internal shutter flap could be toggled open, to enable the internal light to shine through the glass and so expose the printing paper.

Its advantage would have been consistency of exposure and the ease of working provided by bright safe lighting from the printer itself.

After exposure, the printing paper was released from the frame, developed, fixed and washed in the conventional manner. The resulting prints were, of course, exactly the same size as the negative. In the days of roll films, when negatives were often 2¼" x 3¼" (6cm x 9cm) such a print size was quite acceptable and made the best of negatives from relatively simply cameras which hadn't the definition for much enlargement.

Since semi-opaque paper negatives cannot be printed by transmitted light, only by reflected light (though it is possible to reduce paper negative opacity by oiling the paper and then making transmitted light contact prints if the paper's grain can be tolerated), it follows that making contact prints from paper negatives isn't practical if good quality is required. This most likely explains why Gratispool chose to offer postcard enlargements, as their paper negative films could only be printed by projection, using reflected light, so it was as easy to make postcard sized prints as any smaller size.

Around 1960 I tried contact printing Gratispool paper negatives by transmitted light in a conventional contact printing frame, but the results were of low contrast and poor definition, due to the texture of the paper negative being superimposed onto the photographic image. To make the negatives more translucent I remember smearing them with some sort of oil or vaseline grease, but it was messy and I didn't continue with it! I gave up Gratispool films at that time and started using conventional celluloid film from Ilford & Kodak.

Contact printing of celluloid negatives is still popular today, but not for making final prints. Its possible to contact print a whole 12 exposure 120 roll film, or a 36 exposure 35mm film, onto a single sheet of 10" x 8" bromide paper, using a special contact printing frame, such as were made by Paterson. The resulting composite print can be filed and serves as a ready means of identifying what is on a particular set of negatives, without the need to handle the negatives or hold them to the light.