There are a wide variety of paper substrates available for digital printing, providing a wide variety of choices for every taste. (A substrate in this context is simply the underlying material on which other materials, such as coatings or ink, are applied). A paper suitable for inkjet printing typically has a paper substrate with a coating that facilitates receipt of inks. There are three main categories of paper substrates for digital printing – RC, art papers, and fiber papers.
RC (Resin-Coated) Papers
Much like in the traditional darkroom days, RC papers provide a combination of very good image quality combined with a reasonable price. RC papers by definition utilize resined plastics in the paper base. Unlike the darkroom days, there are no particular concerns with longevity – good RC papers have comparable archival characteristics to the ‘fine art’ papers. RC papers have a look and feel like some photo lab prints and thus seem like a ‘real’ photograph to many, but most (including myself) feel that the more plastic feel and look is undesirable when compared to art and fiber-based papers. RC papers using earlier technology had problems with gloss differential and/or bronzing but those problems have been generally ameliorated with newer ink technology. Another issue with RC papers that has not been entirely resolved is the issue of outgassing – it is recommended that the papers be cured (such as by laying a sheet over the print for one day) to avoid the possibility of fogging of glass or plexiglass when the print is framed.
Art Papers
Art papers include a wide variety of papers, particular with respect to surface texture as they range from ultrasmooth to highly textured watercolor-type papers. Art papers use matte black inks on digital printers and typically provide somewhat less dynamic range and blacks that are not quite as deep. Art papers counter these disadvantages with an elegant feel and a complete lack of gloss differential issues or reflections. The base material for art papers is usually cotton rag or alpha cellulose, but new materials are also being used, such as sugar cane and bamboo.
Cotton Rag papers were traditionally manufactured from torn cotton rags but are now typically manufactured from a pulp of cotton linters, which are fibers that adhere to cottonseed after ginning. A pulp is any cellulose plant fiber that has been cleaned and beaten into a wet mixture. Plant fibers may include wood, cotton, linen, and the like. Cotton rag papers for digital printing are often traditional art papers (e.g., textured watercolor or other matte papers) on which a special coating has been applied to properly receive inks.
Alpha Cellulose papers. Cellulose, the chief constituent of cell walls of plants, is the result of processing of plant tissue designed to yield cellulose. High alpha cellulose papers are a particularly pure form of wood pulp considered to have comparable longevity and archival characteristics as cotton or other plant fibers.
Hahnemühle provides art papers with alternative materials, as well. Hahnemühle Fine Art Bamboo Paper is made from 90% bamboo (a highly renewable resource) and 10% recycled cotton rag. Hahnemühle Fine Art Sugar Cane Paper is made of 75% of sugar cane waste byproduct (called bagasse) and 25% recycled cotton.
Fiber-based (fibre-based) Papers
Fiber-based (FB) papers are relatively new and are an attempt to replicate fiber-based darkroom prints in the digital darkroom. FB digital printing papers typically have a glossy or semi-gloss surface over a fiber-based substrate, provided a “fine art” feel along with stellar image quality. They bridge the gap between RC and art papers by providing a cotton rag or alpha-cellulose backing with a non-matte surface that can provide deeper blacks and more color range.
One type of FB paper that has become very popular recently is the baryta paper. Baryta papers have a multi-layer coating that includes barium sulfate, a white clay-like substance, over a paper base such as alpha cellulose or cotton rag. The baryta gives the paper much of its smoothness, whitepoint, and, interestingly, a smell just a bit reminiscent of the darkroom. Baryta (pronounced bah-RYE-tah) papers have their origin in the traditional darkroom as fiber-based silver gelatin prints typically used a white layer of barium-sulphate gelatin applied to the paper ground and beneath the light-sensitive layer to help provide pure whites and rich blacks. As such, the use of baryta in papers for photographic printing has a long history of archival permanence.
Inkjet-compatible baryta papers use a multi-layer coating that includes baryta over a base such as cotton rag or alpha cellulose. Popular baryta papers for digital printing include Ilford Galerie Gold Fiber Silk 310 gsm (and its sister Canson Infinity Bartya Photographique 310 gsm), Harman Gloss FB Al, and one of my all-time favorites, Hahnemühle Photo Rag Baryta 315gsm.
Baryta papers for the digital darkroom have all the archival characteristics you would like and importantly, have a very similar look and feel to great air-dried fiber-based silver-gelatin papers. Similar, mind you, is not the same as identical – while these papers do appear very similar to traditional darkroom papers, there are of course differences visible to the discerning eye, most notably in how the ink sits on the surface rather than being embedded in the surface in a darkroom print. But they are mighty close and are wonderful objects in their own right, and that is ultimately what is important to me as a printer and photographer – not how closely the end result matches traditional methods, but how it stands on its own.
