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<p>[QUOTE=&quot;2manybooks, post: 11127257, member: 8267&quot;]Very interesting. I have not encountered examples of ivorytypes before. As these appear to date before the invention of celluloid in 1868 (based on the clothing styles), I was curious about what material was used for this &quot;factitious ivory&quot;. This is what I have found - </p><p><br /></p><p>MAYALL, J. E.</p><p>“Photographs in Factitious Ivory.” ANNUAL OF SCIENTIFIC DISCOVERY, OR YEAR-BOOK OF FACTS IN SCIENCE AND ART FOR 1858 (1858): 230-231. [“An invention by Mr. J. E. Mayall, the well-known London photographer, relates to the use of artificial ivory for receiving photographic pictures instead of glass or paper. This artificial material, which possesses all the properties and beautiful finish of ivory, and allows of any subsequent tinting of the image, and the obtainment of superior softness in the semitints, is what is known in France as Pinson’s artificial ivory, consisting of a compound of gelatine and alumina. This material is prepared in the form of slabs, for the photographer’s use, in this way: The tablets or slabs are composed of gelatine or glue in its natural state, and are immersed in a bath of alumina, which is held in solution by sulphuric or acetic acid; by this means a complete combination takes place between the alumina and the gelatine or glue. The tablets or slabs should remain in the bath a sufficient time to become thick enough for the purpose for which they are required, and to allow the alumina to entirely penetrate them and incorporate itself therewith ; they are then removed and allowed to dry or harden, when they may be dressed and polished by any of the ordinary and well-known processes for polishing ivory. Artificial ivory tablets, capable of bearing a fine polish, may also be made by mixing alumina directly with gelatine or glue; but this process is not so satisfactory as the process hereinbefore described, since the thickening produced by the admixture of the alumina with the gelatine, renders the manufacture of the sheets both difficult and expensive. Another composition of artificial ivory which is employed, consists of equal portions of bone or ivory dust, used either separately or combined, and albumen or gelatine, the whole being worked into a paste, and afterwards rolled out into sheets by suitable rolling or flattening mechanism. The sheets are then allowed to harden by exposure to the atmosphere, and are cut into slabs or tablets of the required size. But it is preferred to use two parts of fine powdered baryta, and one part of albumen, well worked together, and rolled out into slabs. The best plan hitherto discovered for working the materials together, is that commonly used in the manufacture of Parian marble; this composition may also be used spread upon paper, if desired. These slabs or tablets are then carefully scraped, to give them a perfectly even surface. They are then washed with alcohol, to remove any impurity therefrom, and are prepared in the ordinary manner to receive positive pictures. The pictures having been printed, the entire slab or tablet may be immersed for a few minutes in a weak solution of nitro-sulphuric acid or nitro-hydrochloric acid, for the purpose of rendering the picture more clear and brilliant. It is then fixed in the usual manner with hypo-sulphite of soda, and is washed, and then dried on a marble or other slab, or under pressure, to prevent it from warping.”]</p><p><a href="https://vintagephotosjohnson.com/?s=factitious+ivory" target="_blank" class="externalLink ProxyLink" data-proxy-href="https://vintagephotosjohnson.com/?s=factitious+ivory" rel="nofollow">https://vintagephotosjohnson.com/?s=factitious+ivory</a>[/QUOTE]</p><p><br /></p>

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