Winter is approaching here in Cincinnati, far too quickly for my taste! But at the Lab we have been thinking about a winter staple a bit differently… The sled! A book sled, that is. This open-topped carrier of bound treasures has become the newest edition to our enclosure family. It is perfect for housing oversized books to be stored flat, as it enables easy transport of these large tomes, without adding too much extra weight.
The sled has been honed and developed over the years by conservation professionals, but it has its roots at the Newberry in Chicago, where they were used to house their large antiphonary collection. I had the privilege of working at the Newberry prior to joining the incredible team here at The Preservation Lab, so the idea of starting to create book sleds at the Lab has been lurking at the back of my mind. At the Newberry, I was able to create my very first book sled, and understand the simple, yet highly functional structure.
Photo of a sled at the Newberry Library courtesy of Henry Harris. Photo of a sled at the Newberry Library courtesy of Henry Harris.
The book sled was refined by Ann Lindsey and Melina Avery from the University of Chicago when they treated and housed a 52-pound antiphonary from their collection. They were able to design a sled with additional walls and stronger reinforcements. Chris Saclolo from the University of Central Florida further enhanced the book sled by adding wall reinforcements and a removable lower tray.
When the Lab received an elephant folio from the University of Cincinnati Classic’s Library that needed treatment and housing, we were able to create the very first book sled at our Lab! Housing a book over 20 inches tall is no easy feat, so we were thrilled to be able to use the experience and advice from our fellow conservation professionals. I worked alongside Chris Voynovich and Catarina Figueirinhas (because 3 minds are so much better than 1) where we problem solved, planned, and constructed this large book sled. The finished sled design closely follows Saclolo’s recommendations, with minor adjustments to the tray, as our book did not have bosses.
Kasie and Chris working together to construct the book sled.
Catarina was able to create a model that we can use as a reference in the future.
Ultimately, the book sled will allow the book, Facsimiles of National Manuscripts of Ireland, to be visible on the shelf while also aiding in transporting the book through the library when needed. It will also prevent additional damage and abrasion to the leather at the spine, which received a reback during treatment.
Facsimiles of National Manuscripts of Ireland in the finished book sled.
We already have additional oversized books in the Lab for treatment, so more sleds will be on the docket this winter!
Please join us for the second lecture in the six-part series – “Making the Fabrica: The Illustrations, Printing, Binding & Publication.” Award-winning cultural historian Dániel Margócsy, PhD, University of Cambridge, will describe the creation of the “Fabrica.” Dr. Margócsy will be joined by Gabrielle Fox, a Cincinnati book binding and preservation expert, who will discuss the bindings of the first and second editions that will be on public display in the Donald C. Harrison Health Sciences Library.
The lecture, free and open to the public, will be held Tuesday, Nov. 16 at 5:30 p.m. in Kresge Auditorium, 231 Albert Sabin Way. In-person activities will be provided under CDC guidelines or local COVID-19 restrictions, with the well-being of all guests remaining the top priority. View UC’s current COVID-19 updates.For those not wishing to attend in person, the lectures will be live streamed via Zoom.
Tune into the Lab’s Instagram the entire week before Halloween, where we’ll be sharing five of the scariest “preservation horrors” that we encounter in our work. It’s bound to be a fun but frightening week that you won’t want to miss!
A very special thank you to our model, Aja Hickman, who also happened to have the wonderful idea for this event!
Join the Preservation Lab staff on Wednesday, October 20th at 3pm (EST) for an quick Instagram Live event centered around a collection of Japanese bindings that were recently conserved and are now in the process of receiving specialized, custom enclosures. We’ll be talking about the two different types of bindings in the collection, creating Japanese four-sided enclosures, why we make models, and answering any questions you might have!
Mark your calendars, or better yet, follow us on Instagram @thepreservationlab for updates, because you won’t want to miss this behind-the-scenes look at what goes on in the Lab. See you then!
One of the exciting things about the Preservation Lab is you never know what’s going to come into the Lab next! Sure, sometimes we know a little bit ahead of time about upcoming projects, but usually the special collections intake meetings are filled with “oohh’s”, “aahh’s” and sometimes “oh no’s”. But it’s not very often that you get to work on a project, here in Cincinnati, while the objects themselves are across the Atlantic. Combine that with RTI (Reflectance Transformation Imaging), a variety of Vesalius related texts, and an opportunity to collaborate with other photographers, and you’ve got a recipe for one exciting project!
Currently in the planning stages, the Winkler Center for the History of the Health Professions will host a series of Cecil Striker lectures and a physical exhibition that will celebrate the work of Andreas Vesalius. The series and exhibition is entitled The Illustrated Human: the Impact of Andreas Vesalius and is sponsored by Stephen and Sandra Joffe. Vesalius was a renowned 16th century author and physician, whose iconic work on human anatomy, De Humani Corporis Fabrica Libri Septem, is considered one of the most influential anatomy books ever written. Three rare first edition Vesalius volumes will be exhibited during this upcoming lecture series, gratuitously on loan from Stephen and Sandra Joffe. Dr. Joffe is a long-time UC supporter and an emeritus faculty member.
For the upcoming exhibit, the Lab will be creating custom supports, as needed, to display the volumes, and providing imaging of various pages and illustrations for promotion. I will also be doing any additional specialized imaging that might be helpful.
Since we believe that some, if not all three bindings coming to Cincinnati, might be original to the volumes, and we immediately thought of RTI and wondered if it could provide new insights to researchers. After seeing the wonders of RTI, via RTI examples from the Lab, the owners of the Vesalius editions were interested in having RTI done on a selection of Vesalius items in their collection, including some that wouldn’t be coming to the Lab. The only hitch? The volumes are at their home in Scotland. The solution: hire a local photographer, Iain McLean, to carry out the capture portion of the RTI in Scotland, and have the files shared with the Lab for processing and rendering. Though Iain is an established commercial photographer with a digital imaging background, RTI was a new adventure for him, so I shared some resources with him, including CHI’s Guide to Highlight Image Capture and some notes and resources created by the Lab during our various capture sessions. Iain and I then met via Zoom in mid- August to discuss the ins and outs of RTI highlight capture prior to his capture session on August 20th. Iain also brought his colleague and fellow photographer, John Linton, into the fold to assist him during the capture session, which I recommended highly because though it might be possible to do RTI solo, I can’t imagine a capture session without my normal collaborator and the Lab’s Assistant Conservator, Catarina Figueirinhas. The session would take double the time and I’d make five times the mistakes without Cat! (Check out a time lapse video of Cat and I doing RTI in the Lab on our YouTube channel).
Iain and John during the capture session, featuring one of my favorite volumes that they captured that day. (This image was taken by Iain and kindly shared with me.)
After a successful test capture session, Iain and John were ready for the main capture session on August 20th. They ended up capturing the front and back covers of seven volumes. Once the massive capture session was completed, Iain shared the jpegs with me so that I could begin processing the images in RTI Builder and then rendering the snapshots in RTI Viewer.
This is a time lapse video of the capture session. (This video was created by Iain and kindly shared with me.)
After processing the 679 images and rendering the snapshots, here are some of my favorite finds:
This a side-by-side of an upper cover. The left image shows the default lighting mode in RTI Viewer and the right show the specular enhancement mode. On the right, just above the center panel, you can see the letters GFV (above the panel) and 1567 (below the panel), which are much more visible with the specular enhancement mode than under normal illumination.Here you can see a detailed composite of another cover’s center panel. On the left is the default/normal illumination mode, the center shows the normals visualization mode, and the right is the specular enhancement mode. You can see by employing the two specialized RTI modes the ornate detail of the cover is far more readable.
This composite of the upper cover features the diffuse gain mode on the upper left half, and the default lighting mode on the lower left half. The diffuse gain mode really accentuates the features of the man in the center panel.
This is a composite of the lower cover of the same volume (my favorite binding of the group). This shows the default on the upper left and specular enhancement on the lower right.
This composite of another upper cover shows the default mode on the left and the specular enhancement mode on the right. With this one, the discoloration of the cover distracts the eye and pulls it away from the detail of the decoration, but with the specular enhancement mode you can eliminate the color completely and modify the secularity so that your eye can focus solely on the elaborate detail.
This was such a fun experience for me, and I really enjoyed collaborating with colleagues outside the conservation field and across the pond! And I look forward to the condition photography of the three volumes and any additional specialized photography that might be helpful.
Special thank you to Stephen and Sandra Joffe for allowing their important collection items to be photographed, and for giving the Lab full permission to use the generated images. Also, a very special thanks to photographers Iain McLean and John Linton for capturing these covers and for collaborating with me on this exciting project.
Today the Preservation Lab says goodbye and thanks to our fearless leader (on the UC-side of the shop) Dan Gottlieb, Associate Dean of Collections and Scholarly Resources. Dan has been with University of Cincinnati Libraries for 48 years and has been our advocate since 2018. His contributions are many as a leader, but as a colleague we’ve always appreciated he thoughtfulness, willingness to lend a hand, and always showing up to our events. We wish you a wonderful retirement Dan!
The Lab recently received a collection of Exposition coins and an Exposition advert that were new acquisitions from UC Libraries’ Engineering Library.
While Ashleigh and Chris took on the housing portion of the project, I, of course, took on the documentation portion. This is one of the few times where scanning the object was actually the best route to take for documentation. I ended up scanning these after they had been safely and fully encapsulated in polyester film, and I was pretty pleased with how these scans turned out. Here are five of the exposition coins (rectos in left column and versos in right column):
These five coins were all encapsulated together with a Vivak backing layer and a 3 mil polyester film top layer, and then spot welded in place. I scanned them at 2400 dpi and then cropped each coin individually. And remarkably, this led to pretty successful scans of each coin while also keeping them safe and secure in the encapsulated package.
You can see how Chris and Ashleigh encapsulated and matted the coins on our Instagram –
If you’ve ever come across an old silver-based print, perhaps in a box in the attic, or an old family photo album, or even in a stored collection in a library archive, you’ve likely seen a pretty common phenomenon known as silver mirroring. Areas of the photograph will have taken on a shiny surface tarnish, a bit like a dull mirror.
Pictured: A “before treatment” image from a 2019 treatment to reduce silver mirroring. Note that the edges are more heavily mirrored than the center. Mirroring most often begins at the edges of a photograph.
There is a fun bit of chemistry involved in this, and we’re going to talk about that today. Note that this is just a quick overview of a LOT of information, so if you’re interested in a deeper dive, the information I’ll be discussing is drawn from the AIC Photographic Chemistry Series, particularly unit two, The Latent Image. The videos discussing the Gurney-Mott Mechanism, Photolytic Silver, and Silver Ion Traps can help provide an even greater understanding of these concepts.
Remember last month, when we went into valence bands and movement of electrons from the ground state to the excited state in order to become available for chemical reactions? Well, now we’re going to look at a bit of what happens once we have that excited electron, and how the reduction of silver ion becomes a silver metal. This process is the basis of photographic image formation, as well as the process that eventually leads to the aforementioned silver mirroring. This is known as the Gurney-Mott Theory.
Pictured: the Gurney-Mott Mechanism. Silver ion (Ag+) gains 1 electron and becomes stable silver metal (Ag0).
So, the light has struck our silver halide ion, and an excited electron has been generated. Now what? Well, first, we have to look at where that electron originates, the halide. Halide atoms, in a vacuum, have only 7 valence electrons. In that state, it’s uncharged, expressed as X0. It’s incredibly reactive this way. It really does not like to be uncharged! Halide atoms follow what is known as the Octet Rule. That is, they prefer to have 8 electrons in its valence band, for maximum stability. An uncharged halide will seek an extra electron to create that stability. When that happens, it becomes an X– ion and has a closed valence shell (it has maximum allowable electrons – it’s closed to additions.)
Pictured: The halide ion, in chemical terms. A stable ion (X–) is struck by light (hv), leading to the escape of an electron (e–). A recaptured electron will return the atom to the X– state.
Once that electron is stimulated enough to reach the conductance band and break free from the halide, it will roam and fall into a lower energy level, where it is drawn what is called a silver ion energy trap. This trap is a region of energy within the silver halide grain that pulls in and holds electrons. The electron is then sensed by a positive silver ion, which then comes seeking to bond with that free electron. The energy trap is the site of all of the reactions within our AgX crystal. These traps can be shallow or deep; deeper traps have higher energy and are more stable reaction sites.
In the early days of silver-based photography, these traps were formed entirely randomly. As you can imagine, it made the reactions a lot harder to control, and created a lot of guesswork and trial and error. Once the process was better understood, chemical sensitizers were introduced into the process to make things more uniform. The most common sensitizer is sulfide (yes, from sulfur; it’s noted as S2-). A sensitizer creates attractive, consistently deep traps for electrons to congregate. It’s a lot like digging a pit to trap a wild animal. Dig a deep pit, and once you lure the animal, it’s a lot harder for it to escape. Here, it’s electrons and the silver ions that will come looking for them in the world’s tiniest single’s bar.
Energy traps are essential to latent image formation. Without them, the meetings between free electrons and silver ions would be totally random, and the resulting photographic materials wouldn’t be very sensitive at all, which is no good. They also wouldn’t be particularly stable, as once you have silver ions and electrons in a trap, you want them to stay there as long as possible.
Now we have our energy trap, our electron, and our silver ion (Ag+). We’re all set for chemical magic. They meet, get friendly, and form silver metal (Ag0). This is the Gurney-Mott Mechanism in a nutshell.
If we can get four of these silver metal atoms to congregate in the trap, they will form a silver speck. Now we’re getting places! This is the key to photosensitivity. The more deep traps we can generate, the more sites of silver speck formation we have, the more sensitivity and better image formation we achieve.
Alas, time takes its toll on all things, including our Ag0 coupling. Silver, you see, isn’t the most stable of partners. It likes being Ag+, and it will work to get back to that state. Eventually, our Ag0 union will dissolve and the Ag+ ion will wander off. When this happens, the freed silver ions will migrate to the surface of a photograph and reduce to become silver sulfide. And that, friends, is how silver mirroring happens.
Hyacinth Tucker (UCL) — Bindery and Conservation Technician
About two years ago, I set upon a mission to gain expertise in the area of identification and treatment of photographic materials. Under the guidance of our conservator, Ashleigh, I developed an education plan that was split between the theory of learning the ins and outs of photograph identification, and the hands-on work of treating pieces that came into the Lab. Of course, these two things go hand in hand. If you can’t identify a piece, you can’t treat it correctly, right?
Fast forward to last year. With the start of the pandemic and the transition to working from home, my education plan changed radically. If I’m not in the Lab, I can’t spend much time on treatment, so I had to get a little creative and work on other ways to learn more.
I am about halfway through the series; a triumph for me, as I have never been one for the study of chemistry. I will say that while it is still very technical, I’ve had a lot of good pegs to hang the information on, owing both to my earlier studies in photograph conservation and my personal history with film photography. It’s been a tremendous thing, viewing things that I learned as a photography student from a different angle. So far, it’s been a great journey.
In this series, I will share with you some of the most fascinating things that I’ve learned so far. My aim will be to keep the technical as simple as possible, for those of you who are like me, still coming to terms with the deeper science. The small bites help it all make sense, I promise. Hopefully, you’ll find it all as interesting as I have.
Before we can understand anything else, we need to talk about halides. What are those and why are they used in photography? Good questions! Halide salts are derived from halogens, which occupy group 7A (column 17) of the Periodic Table of Elements (see below.) Halide salts are used in photographic emulsions that are spread over a substrate (such as paper or film) before the substrate is exposed to light. The silver halides react to the light to form an image when developed.
I should note here that silver gelatin prints, albumen, and collodion photographs all utilize silver halides in their chemical composition. However, silver gelatin is unique among the three in that it is the only one that uses a true emulsion; in albumen and collodion coatings, the halides rest on the surface.
Photograph – silver gelatin process
Photograph – albumin process
Photograph – collodion process
In forming the silver gelatin emulsion, halide salts are combined with silver nitrate and water to form silver halides, the compound at the core of silver gelatin photography. Silver nitrate is pretty much universally used regardless of halide salt, as it is water soluble (it dissolves) but not too much so. The freed silver will look for a bond partner, and the halides in halide salt fits the bill. As a result, silver nitrate, when combined with a halide salt in water, will result in silver halide and a left over salt.
This reaction, which seems like a lot, I know, is referred to for our purposes as “The Emulsification Equation.” To refresh our memories a bit, an emulsification is a liquid (here, gelatin) that contains fine particles of another liquid (the silver halide) without fully combining. Think mayonnaise, or butter. (This isn’t perfectly analogous, as silver halides are crystalline solids and not liquid fats, but the basic idea is the same.)
Chemically speaking, that reaction looks like this:
Equation for emulsification
As a quick reminder, Ag = silver, N = Nitrogen, O = Oxygen, K = Potassium, and Cl = Chlorine.
Now, if you’ll look at the image of the halogen column of the table below, you’ll see a number of options for salts to combine with silver nitrate. Older emulsions involved bromine or iodine; more modern emulsions tend toward chlorine. Crystals formed from silver chloride salts are much more uniform in structure, which makes its use outcomes much more predictable.
Salts that will combine with silver nitrate
I’m sure you’ve noticed that we’ve got a couple of halogens unaccounted for, namely fluorine and astatine. Neither of these are used for this kind of work, and for good reason. Fluorine, for its part, is very water soluble. Very water soluble. To put it in perspective, sodium chloride (regular table salt) is about 35% water soluble. I’m sure that in the course of cooking, we’ve all dissolved salt in water, and you can recall how relatively simple that is to do, though not without some small effort. Well, fluorine salts are about 172% water soluble! You could use it for your emulsion, but moments after developing an image in a water-based solution, you’d see it dissolve before your eyes.
I’ll note here very briefly that chlorine, bromine, and iodine are also more soluble than table salt, but not nearly as much as fluorine, making them perfect partners for our silver ions.
Meanwhile, astatine is…well, it’s radioactive. I think you can see the problem with this one.
And there you have it, a short and hopefully painless explanation of the humble halide in silver-based photography. In the coming months, we’ll be looking at other fascinating aspects of halides and our Emulsification Equation.
Hyacinth Tucker (UCL) —- Bindery and Conservation Technician
One of our most recent additions to our channel is the recording of our Virtual Lab Tour and Live Q&A, hosted by the Cincinnati & Hamilton County Public Library, which took place on Tuesday. If you weren’t able to join us live, please take a look; it was a very fun event and we had so many great questions from our live viewers.
Make sure to subscribe to our channel so that you can stay up to date on any new videos we add! And don’t forget to like videos, and we’d love to hear about what you’d like to see more of from us in the future.
