The problem with glass
Glass slides are fragile. They can be broken through handling or during any form of transit. Considering this, we took many measures to protect the slides. Slides can easily break if dropped, so all slides were handled above a soft surface. Unfortunately, some slides were damaged prior to arriving at the WCSU Archives and Special Collections. The slide shown to the upper and lower left has a severe crack across the front-facing glass plane. Currently, the paper tape around the edges holds it together. Unfortunately, slides are heavy when stored in mass quantities. This makes moving and handling the slides difficult and increases the chance of slides being dropped or broken whenever they are moved.
The surface crack of the slide has exposed the emulsion to open air. Upon further examination, a crack in the emulsion can be seen. This is because the emulsion is separating from the glass plane. During projection, glass slides withstand mass amounts of heat from the projector's light source. The heating and cooling of glass the slide to shrink and expand. Without proper support from the opposing glass plane, the emulsion can not move with the expanding class. As a result, the emulsion can crack and flake. In the upper right-hand corner of the slide, a cloud-like shape can be seen. This is referred to as "blooming," and is likely caused by moisture exposure. This damage may be a chemical reaction, trapped water, or mold growth. Emulsion damage is especially visible when projected and can severely obscure the original image (see image below).
Storage and prevention
One way to reduce the risk of damage is to store slides in a protective sleeve. This keeps slides from scratching each other, allows the curator to write identifying information on the sleeve, and keeps fingerprints off the glass. However, it is a preferred practice to handle fragile materials with white gloves. This further reduces the changes in fingerprints and keeps the skin's oils away from the artifact in question. The sleeve itself is made of archival material. This means that the paper is free from acids and chemicals that may further damage the materials it comes in contact with.
Also, glass is dense, so we store the glass slides in small boxes. If we stored them in larger boxes the boxes would be very heavy. Separating the collection into smaller boxes also means that if one box is dropped, fewer slides are damaged. Pictured to the upper and lower right is the archival storage for the lantern slide collection. There are a total of 9 boxes that house the 450~ slides within the collection. Each box is made of archival material similar to that of the aforementioned sleeves. The material is acid-free which reduces the chance of damage caused by the storage itself. Also, each box has a clear coating that protects the boxes from moisture damage. This means that the box can have limited exposure to water without the contents inside being damaged or destroyed.
Each box contains supports behind and to the side of the slides. This keeps the slides upright and reduces the chances of slides being distorted or shuffled whenever a box is moved. Without the supports, the slides could hit one another and cracks could occur. The exterior is labeled with identifiers that match our online collection. In addition, the label can be removed in case adjustments need to be made or the slides need to be relocated