Choosing the Best Paper for Platinum/Palladium Printing

Many hand-coated photographic processes can render an image by the formation of metal particles, such as silver, within the flattened, macaroni-like, cellulosic structure of paper. Consider the kallitype, argyrotype or any other siderotype process. A platinum and palladium print, however, has a different signature from all other processes. These precious metals are capable of engaging with cellulose in the finest manner, as nanoparticles, to the very ‘edge’ of what we call paper-base white. As a result, print highlights take on nuanced values. At the other end of the tonal scale, dark values are separated better than most other processes, and remain expressive, whispering in the shadows. These dark tones certainly do not have the deep, black values of emulsion-based silver-gelatin printing processes. Yet, blacks are rarely an unresolved mass of monotone—akin to the way we actually see. It is for these reasons that the overall experience of looking at a well-printed platinum/palladium image is often described as being subtle and intimate. The role of paper in conveying these qualities is impossible to ignore. Most obviously, there is the visual experience of paper: its color and surface texture.

The platinum/palladium sensitizer solution is imbibed into the surface fibers of the paper sheet, where it comes into intimate chemical contact with the cellulose – and with every other substance that happens to be present in the paper. Depending on the manufacturing process, some of these substances may be hostile to the photochemistry. That paper is not an inert component of the process was recognized even from the earliest decades of photography’s invention. Frustratingly, unlike all other aspects of printing-out platinum/palladium, the precise makeup of this essential material is usually beyond our control and even knowledge (papermakers are notoriously secretive about their recipes). Always be on the lookout for a suitable paper, know how to test it, and then, on finding a good stock, be prepared to buy as much of it as you can afford.

Ultimately, an ideal paper will display the physical characteristic of resisting absorption of sensitizer solution long enough for it to be easily and uniformly distributed across the surface, and then absorbing it evenly to within about 0.1 mm, just below the paper’s surface. This paper will also present a benign chemical environment that permits the formation of full tonal values (i.e. a maximum black, which usually has an absolute optical reflectance density value of around 1.4) and a thorough clearing of unexposed areas to paper base white. The following characteristics are most significant in choosing a paper that helps us meet these goals.

• Furnish: a high cellulose furnish, derived from any single source such as cotton, linen, hemp, gampi, or delignified softwood
• Texture: a wove mold rather than laid; any watermark excludable from the picture area
• Surface: smooth, hot-pressed (HP) or cold-pressed (CP) surface
• Sizing: internal sizing with Aquapel™ or similar alkylketene dimer (AKD)
• Buffer: no alkaline buffering agents such as calcium carbonate
• Weight: a weight of ca. 160 g/m2 to 360 g/m2 (heavier for large printed sheets)
• Additives: minimal, and preferably no other additives
• Absorption: the capacity to absorb between 20 and 30 milliliters of sensitizer solution per 1 square meter of surface area (20 to 30 ml/m2).

Recommended Paper
This list only includes papers that are available as of the beginning of 2020, and work for platinum, palladium and platinum/palladium printing. Not all are easily available in all regions. For a longer list of papers and suppliers, please refer to Appendix IV Resources, and the book’s online resource to access up-to-date information. Note that naming conventions for any given paper may stay the same but its formulae, and even mill-source may change. Be sure to test each batch.

Arches Platine
Made by a French mill dating back to the 15th century, Arches Platine was developed in close consultation with the photographer/printer Martin Axon and others. This is a 100% cotton rag furnish, no buffer—or, as the manufacturer puts it, without an alkaline reserve, pH neutral, no optical brightening agents, and made on a cylinder mold. It comes in two weights and two sizes, all with deckled edges. Each side presents some differences in image quality. Arches Platine’s dimensional stability is high, with negligible change from the original package-dimensions to the processed and dry print. It has now gone through several productions, each with slight variations in the formula. Consequently, each batch requires platinum/palladium printers to make small adjustments. The current batch, made without any watermarks, works well without Tween, and benefits from the addition of glycerin to the sensitizer. This paper is widely used in other siderotype processes.

Buxton Rag
Herschel Platinotype
Both of these handmade papers are produced by Ruscombe Mill. Buxton paper was developed in 1993 by the Mill’s original master papermaker, Chris Bingham, when its studios were in Gloucestershire, England, out of a collaboration with Mike Ware. The name that Chris chose for it –Buxton– was a reference to Mike’s home town, which has been noted historically since Roman times for its spa waters, as Aquae Arnemetiae. In the late 1990s, Ruscombe Mill was relocated to Margaux in France, in the heart of the Haut Médoc, where it shares the excellent local water with the winemakers. Buxton was made from the finest quality long cotton fiber, nearly 100% α-cellulose, which is stronger than papers made from cotton linters. The mill had problems with the quality of cotton furnishings supply in 2011 (which seem to have now been resolved as the mill has reintroduced a Buxton Rag paper), which eventually caused Chris Bingham to design a new paper. This new paper differs from all other alternative process papers in being handmade from 100% linen cellulose fiber (made entirely from the best quality flax, not cotton): he decided to name it ‘Herschel Platinotype’ paper. Linen fiber is derived from the stem of the Common Flax plant, Linum usitatissimum, and has a similar size to cotton, but is cylindrical with a thick cell wall and a lumen (the tubular fiber’s internal space or opening) of relatively small diameter. It has periodic knots or nodules, resembling bamboo. When beaten, the flax fibrillates more extensively than cotton and forms a stronger, less elastic paper sheet. These differences play out ultimately in the siderotype process—it is possible that the structure of the flax fiber may enhance its ability to retain the metal nanoparticles that lead to image formation.
Both Buxton Rag and Herschel Platine are cold-pressed, with an attractive ‘tooth’ to give life to the surface, which does not change significantly after wet processing. The papers are internally sized with neutral alkylketene dimer (AKD), have a pH of approximately 7.5 and are very close to neutral, there are no additives, and they display a natural bright white color. There is no difference between wire and felt surfaces with regard to image formation, though each side may respond slightly differently when being coated. Use Tween with the sensitizer.

Revere Platinum
Related to the Magnani paper mill in Italy, but commissioned and distributed exclusively by Legion Paper Company based in New York, Revere Platinum is currently one of the most compatible papers for platinum/palladium and other siderotype processes. Based on a production by Magnani around 2011, variations in the formula since then have left printers veering from getting very good to disappointing results with the paper. Legion Paper is now committed to making a paper for alternative and siderotype processes, and the current production is proving to be very consistent. Revere Platinum is a 100% cotton paper, with an internal sizing agent, a smooth hot-pressed surface, and no buffering agent. It comes in one weight and two sheet sizes. Both sides are very similar, and yield good results. It is best to use a combination of Tween and glycerin when coating this paper. It has good wet strength and dimensional stability.

Reich CT
Commissioned and distributed by the family-owned Reich Paper company, Reich (pronounced ‘reesh’) CT is a naturally translucent paper with unusual properties. It may be the only paper in the platinum/palladium materials list that has a food-safe certification! The paper is manufactured in England, using technology that was initially developed as a part of a strategic effort to prepare for World War II—all of Britain’s tracing, or ‘engineering’, paper was being imported during the 1930s, and mostly from Germany. Now made from 100% cellulose derived from a combination of northern hardwoods and southern softwoods, the fibers of which undergo heavy cellular defibrillation, Reich CT is a superfine, dense and impervious paper. Due to the special processes employed in the manufacture of translucent papers, this paper does not require heavy calendering (contrary to the impression one gets from its smooth surface), but is highly dimensionally unstable. It shrinks by as much as 25% by the end of the production process. From this state, its dimensional dynamics are a bit like a yoyo. The paper, relative to the original dry ‘packet’ dimensions, expands by about 2% in the grain, and an astonishing 13% in the cross-grain direction when fully wet. It then, perplexingly, and depending on how much pressure is applied while drying the sheet, shrinks by about 1% in the grain direction and increases by about 5% in the cross-grain of the original dry dimensions. These dynamics can be compensated for to some extend when preparing digital negatives. Available in a number of weights which are described as ‘bond’ units: the thinner papers, 17# 24# and 30# have to be handled with the greatest of care during processing.

Wyndstone Vellum
This paper has many of the same characteristics as Reich CT, but is made in Germany. The main difference is that it is a bit more difficult and expensive to acquire in the USA.

I offer up some thoughts on coating translucent papers like Reich CT and Wyndstone vellum. This may also apply to thin papers. Before you begin working with this paper, it’s important to identify the wire and felt sides. The difference isn’t immediately visible on the dry, uncoated paper, but will become apparent once your print is dry. When cutting down your full sheets, stack all pieces with the same side facing up. After making your first print from this stack, you’ll be able to determine identify the surface and note this on your stack of uncoated papers. There’s also a subtle physical clue you can use – the paper’s natural curl reveals the felt surface as the convex (outward-curving) side.
For coating an 8×10 inch area, you’ll want to use 1.2 to 1.3 mL of solution, which allows for five complete passes. This paper undergoes a significant dimensional change when wet. Thus, be sure to secure it to the coating surface such that you are coating in the grain direction.
During the exposure phase, keep a piece of white paper or thin card nearby for inspection purposes. Slip this between your coated paper and the negative to make assessment much easier. At full print-out, the highlight values (zones VII through VIII) remain difficult to see and will only become clearly visible once the paper is completely dry and placed on an opaque white surface.
For the final drying phase, drip-dry your washed print by placing it on a vertical sheet of plexiglass, perspex, or glass. After surface water has drained away (approximately 5 minutes), place the print between blotting papers under very light pressure. Change these blotting papers frequently – every 5-10 minutes initially, then at longer intervals as the paper approaches dryness.
Once completely dry, you can press the sheet under pressure or in a dry mounting press for final finishing.