Jennifer McGlinchey started her impressive talk with an explanation of the history of lists of photographic paper sizes. She stated that there were no available references that have lists of ‘standard’ sizes. In fact, the lists of sizes they were able to find were very small, and also corresponded to very specific time periods. Further research suggests that these sizes were not considered standard and were certainly not inclusive of all sizes used. Rather than identify ‘standard’ sizes, she identified ‘common’ sizes by the criteria that they appear in five or more of the references. These she concluded were ‘de facto standard sizes.’ For the study, McGlinchey used Paul Messier’s extraordinary paper collection which consists of over 5,000 samples of silver gelatin photographic paper, as well as 9 manufacturer’s sample books and pricelists and 6 encyclopedias: http://www.paulmessier.com/
The use of English-language publications from a few geographic locations (US and Europe) may have been limiting, but in fact, there are very few references from other geographical areas. Concluding that there were common rather than standard sizes is not to say that there were no attempts to standardize paper sizes, but the attempts were never very successful. The result of the study was that she identified over 200 distinct sizes, just over half of which occurred only once. She identified 32 de facto standard sizes. Many of the sizes considered common now in the USA, such as 4×6 and 5×7 inches, are included in that list, but many sizes which are no longer manufactured are also on that list. This includes smaller sizes like 2.5 x 2.5 inch, which were much more common in early days of gelatin silver printing. She mentioned that the measurements for papers grouped together as the same size allowed for a difference of +/1 5 mm along each dimension, to account for natural expansion/contraction, ferrotyping, and so on, which could account for small dimensional changes. As part of the research they also evaluated common thicknesses of silver gelatin paper, and found three de facto standards. The most common was ‘single weight,’ followed by ‘double,’ and finally ‘medium.’ Double weight papers fall above 0.25 mm, medium weight papers under 0.25 and single weight papers under 0.2 mm. The double weight paper started get thicker in the 1930s until the 1950s and then got thinner again, so manufacturers changed the thicknesses over time but not the terminology. It was also found that five common aspect ratios occurred in 88% of the de facto standard sizes. This implies that scaling relationships were a factor for determining silver gelatin DOP paper sizes. Characterization by aspect ratio not only simplifies the dimensional diversity of silver gelatin paper by emphasizing their scaling relationships, but also highlights their relationship with other media. For example, 6:5 is common mainly with plate sizes, 5:4 is the aspect ratio of many large format films. 4:3 is the first motion picture aspect ratio and 8:5 is the golden ratio.
The measurements and other data were recorded in spreadsheets (the full results were published in JAIC, Volume 53, Issue 4 (November, 2014), pp. 219-235). It led to the conclusion that there is no easy answer to these questions. No system of standard paper sizes was successfully put in place for photographic papers. Additionally, available sizes varied widely over time and across geographic boundaries.
This research can be utilized in identification of artist’s methods and paper preferences. One useful application is to study photograms. This technique was used to great effect by Man Ray and Laszlo Maholy-Nagy, contemporaries working in France and Germany respectively. Of course, each print is unique, because it would be difficult to replicate the exact condition since no negative has been used. Of a selection of 163 prints by Man Ray dating from 1920 to 1940, there were 88 photograms and 75 traditional prints from negatives. Compared with the de facto standard sizes identified by this research, the dimensions of 39 Man Ray 