FILIGRANE A photographic process for water-marking paper, invented by W. B. Woodbury. A gelatine relief of the design is made by the Woodbury type process, and when thoroughly hard and dry is passed through a rolling press with the paper to be water-marked. The result is that the paper is pressed thinner in some parts than in others, the thin parts appearing much lighter. On holding the paper up to the light a water marked image is seen. The relief can be used a large number of times.
FILM (Pr., Pellicule ; Ger., Film) This term is applied to the surface which carries the sensitive silver salt : thus the film side of a paper or plate (Fr., Pellicule ; Ger., Schicht); but it has also become very generally applied to distinguish any flexible support from glass plates. The subject of flexible supports can for historical purposes be most readily dealt with by dividing it into the following classes : (I) negative paper ; (2) stripping films ; (3) cut films ; (4) roll films.
Negative paper was, of course, one of the first forms of negative material, and was intro duced by Fox Talbot, in 1839, who also sug gested making the finished negative more traus lucent by waxing it. Le Gray, in 1854, intro duced the wax paper process, in which the paper was waxed prior to sensitising. In Fox Talbot and Malone took out a patent for a resin-coated paper which was used by Newton in 185o, Le Gray in 1852, and Tillard in Crawford in 1854 used collodion-coated paper, and Geoffray in 1856 impregnated paper with rubber solution, fastened it to a glass plate coated with glycerine, coated it with collodion, and afterwards stripped it. Corbin in 1858 used collodionised paper ; and Marion in 1863 also used dry collodion paper. Laoureux in 1878 used a wax paper, which was rubbed with French chalk, coated with collodion according to the bath process, and the fixed negative was squeegeed down to a sheet of gelatinised glass whilst still damp, allowed to dry, and then stripped from the glass. In 1879, Ferrier, of Paris, patented a film of collodion and gelatine, and in the same year Stebbing introduced gelatino-bromide films on a hardened gelatine skin. Palmer, of Liverpool, in 1881 produced a film of gelatine and oxgall. In 1882 Morgan, of Morgan and Kidd, introduced negative paper, and Warnerke in 1884 made paper coated on both sides with emulsion, so as to avoid the curling of the paper and negatives. In 1885 Woodbury and Vergara utilised a paper made transparent with resins, etc. ; and ordinary negative paper was produced by Wilde, of Gorlitz. Eastman in 1885, Moh in 1898, Lumiere, the Thornton Film Co., in 1900 (paperoid films), and Gaedicke in 1889, used thin varnished tracing paper.
Stripping films were made by Milmson in 1877, Ferran and Pauli in 1880, Thiebault in 1886, Wilde in 1887, Moh in 1898, Balagny in 1898, Hofmann in 19o1, Goldbacher in 19o1, the Thornton Film Co. in 1901, and Wellington in 1901. In all these the paper was prepared either with a soluble gelatine film, or wax, rubber, or resin, which allowed the finished negative to be stripped from the paper sup port.
Cut celluloid ,films were first suggested by Fourtier (France) in 1881, but Carbutt (U.S.A.) seems to have been the first to introduce them commercially in 1888, though he had made some in 1884. In 1882 Thamphrey (Birmingham) introduced a "flexible glass" support, consisting of gelatine and collodion, and Moh in 189o, and Raphael in 1892, used thin sheets of mica.
Proedman in 1887 introduced a support of bichromated gelatine which had been rendered insoluble by exposure to light ; Stebbing in z879 used a hardened gelatine film between two films of collodion ; and Wilde in 1883 used insoluble gelatine and collodion. Balagny in 1886 used alternate layers of collodion, varnish, and gelatine. In recent years most plate makers have produced cut celluloid films one hundredth of an inch in thickness.
Roll films seem to have been first suggested by lielhuish and Spencer in 1854, and by Merritt and Warnerke in England and Captain Barr in India in z873. Barr was the first to suggest the present system of using a black material at the back of the film, which was contained beyond the ends of the sensitive material (then paper) to protect it from light. Roll celluloid films appear to have been con ceived first by Goodwin (U.S.A.) in 1887, although the patent was not granted till 1898 ; while this patent was lying in the American patent office, Reichenbach, of the Eastman Kodak Co., applied for a similar patent, which, like Good win's, included the " non-curling " layer of gelatine on the back of the celluloid. Cody, of the Blair Camera Co., patented in 1894 the use of the now well-known daylight loading cartridge. Many of the manufacturers who are mentioned as making cut stripping films also prepared roll films, but the celluloid, about rho- in. thick, is now almost universally used.
The treatment of films, as regards develop ment and fixing, is precisely the same as for plates. The only point to which attention should be directed is the keeping power of the emulsion when this is coated on celluloid, and though this is generally recognised to be practically limited to twelve months after coating, instances have been recorded of films—especially cut films —being fit for use after five years. This possibly can be explained by the different state of dry ness of the support.
In process work, the word " film " is applied in several ways. There is the film obtained by stripping negatives. The " Lotus " film was introduced by Mawson and Swan to facilitate the obtaining, by stripping, of film negatives, these films being of hardened gelatine of sub stantial thickness.
The gelatine films known as " Shading Mediums," often simply called " films," have lines, stipples, or patterns moulded on their surface, so that they can be inked and the pattern transferred by rubbing down with a stylus, or by pressure with a small rubber roller.
The " Norwich Film " is a transparent gela tine film grained on one side for drawing upon in pencil, crayon, or ink, according to the degree of fineness or coarseness of the grain. By making the drawing with a greasy ink the surface can afterwards be flowed over with a non-actinic alcohol soluble varnish, which will not affect the drawing. The latter can then be washed away with turpentine, leaving the lines or granu lations transparent, so that the film becomes a negative which can be printed from by any photographic process. If the film is drawn on with lithographic crayon or lithographic transfer ink, the drawing may be transferred in the usual lithographic manner by damping the gelatine and running through a press in contact with stone or zinc.