By Jess Ortegon
Over the years, Northwestern conservation staff have worked on a few sections of the Siege and Commune of Paris (ca. 1870-1871) collection from the Charles Deering McCormick Library of Special Collections and University Archives: photographs, caricatures, and now as part of my Conservation Residency, a collection of over 1,000 printed posters.
These posters were printed beginning approximately 1869—before the Siege of Paris by allied German states lead by Prussia—well through 1887, more than 16 years after the Commune de Paris (the Paris Commune) was defeated by the government of Versailles during the infamous “Bloody Week.” The posters vary in size, color, and format: some were over 5 feet in length, while others were meant to be cut up and disseminated among Parisians as tickets. While most of the posters were simple black printed text on cream-colored papers, as this was a time of invention and industrial revolution, others were printed on colorful paper. The subject matter of the posters also varied, covering topics such as rationing bread, calls-to-arms, political rallies, theater shows, and even where to find the cheapest potatoes.
I was tasked with supervising this collection project, organizing each step from the survey to housing, and ensuring that the project stayed on target with its goals. Large projects like these can be intimidating to oversee because of the sheer number of items, but behind each one is a team of conservators, curators, and collections managers to share the work.
The poster collection arrived at the conservation lab in paper folders stored in various boxes, often packed full.
No matter how large or small, conservation projects start with a survey to better understand the general needs and scope of a collection. After a survey, we then narrow in the focus to target specific concerns. My goals for surveying the poster collection were to get a rough estimate of how many and what kinds of posters there were and to identify common physical condition issues. I found a total of just over 1,000 posters, 262 of which were printed on colored paper, and 13 that we class as “oversized,” or too large to fit in our 3×4-foot drawers. Despite the varied sizes and topics, what most posters had in common was their condition: dirty, folded, and torn along folds and edges, or some combination of the two. The housings for the posters had issues as well; limp paper folders were too small to fit the posters and boxes were falling apart from the weight of the items.
The posters had a variety of damages from folds to being torn to pieces.
I started organizing the project over my 2-year residency at Northwestern by breaking it down into three steps of treatment: surface cleaning and flattening, mending, and housing. Because so many of the posters were made from similar materials and had similar condition issues, I developed treatment approaches that address the bulk of the collection while leaving room for any treatment that would require more specialized techniques.
Treatment began with gentle surface cleaning with cosmetic sponges followed by humidification and flattening using a specialized rolled humidification technique. This system uses a sandwich of materials that rolls out to provide overall humidification for large individual posters or multiple smaller ones.
Repair tissues and wheat starch paste were used for mending most posters while washing and lining were used for posters with significant losses or those in pieces.
The next treatment steps were broken down into two groups: posters that needed straightforward mending to repair tears, and posters that needed more specialized techniques to address complex issues. These techniques included rehousing brittle posters, removing damaging hinges, and piecing back together tattered and torn posters by lining (backing with a thin, long-fiber Asian paper). Once treated, the posters were housed in large folders in flat file drawers.
Even after 150 years the posters printed on colored paper were still quite vibrant.
The posters printed on colored paper required a little research before treatment could start. The 19th century saw a boom in new materials used to make vibrant colors, the most popular being aniline dyes. These dyes are sensitive to moisture, which was a major concern since many of our treatment methods use some kind of moisture, be it humidification or mending. Research did not conclusively find aniline dyes, but it did identify the pigment chrome yellow. Due to this discovery, some of the colored posters were minimally surface cleaned and flattened, but most were not. Instead they were housed in polyester film sleeves for an extra layer of protection during handling.
Although it may not be surprising for a collection of this size, this project totaled more than 900 hours of work over the last two years – less than an hour per poster. Just cleaning and flattening alone took over 300 hours! But that work was never done alone. While I supervised this project, all my decisions and treatment protocols were the result of the expertise and teamwork of conservation lab coworkers alongside frequent collaboration and communication with curators and collections management.
At the time of writing, this project is nearing its completion with only final treatment and housing to be done. Mending the oversized posters will become a project all its own, though they are currently stabilized in rolled storage. Additionally, the research findings for the investigation of the colored posters will be presented in detail at the 37th biennial International Association of Paper Historians (IPH) Congress in Oslo, Norway, along with a publication in Studies in Conservation expected in 2025.
Many hands make light work, so thank you to everyone who lent theirs for the success of this incredible project. Vive la Commune!