Topics in Photographic Preservation 2007, Volume 12, Article 26 (pp. 182-185)

Housing Glass Transparencies

Katharine Whitman

As part of the Didactic Negative Project, funded through the Mellon Collaborative Workshops in Photograph Conservation, this paper will describe the design and construction of the housings created for the project. The housings were designed for a set of six collodion negatives, made by France Scully Osterman, and intended as didactic learning tools for the five graduate schools for conservation in North America, and the Advanced Residency Program. The design was evolved at the George Eastman House in Rochester, New York, in collaboration with Kelly Thielen, Jiuan-Jiuan Chen and France Scully Osterman.

These housings are aesthetically pleasing, while allowing both transmitted light and reflected light viewing, for inspection of the entire plate, and for easy removal of the plate from the housing. A three-layer rag board design, with Mylar windows, was devised to meet these requirements. It is recommended that black rag board be used because it will hide fingerprints and wear. This design varies slightly from the original project: reinforcing.001″ Mylar® has been added to a lining paper window and a replaceable Mylar® flap has been built into the folder.

Materials List:

4-ply Black rag board
Black linen tape
Black lining paper
Mylar® polyester film -.004″
Mylar® polyester film -.001″
Neodymium disc magnets - 3/8″ dia. × 1/32″ thick
3M #415 double-coated tape, 1/2″
Polyvinyl acetate (PVA) adhesive

Assembly Procedure:

The plate should be stored in the housing binder side toward the flap. To remove the plate from the housing, lay the folder flat on a surface before opening it. Place an index finger over the thumbhole and gently slide the Mylar® slightly away from the right edge to create an arch in the Mylar, then insert a finger under the arch to pull the flap away (Figure 9). Do not keep sliding the Mylar® so that it rubs on the binder of the plate; this risks damaging the image. To remove the plate, place a finger in the thumbhole and gently lift the plate up and out (Figure 10).


Figure 9. Lifting the Mylar flap.


Figure 10. Removing the glass plate.

This housing is versatile and permits safe viewing of glass transparencies (Figure 11). When the folder is closed, the entire plate can be examined without direct handling. The removable flap is replaceable should it become damaged from normal handling. It is recommended that black rag board and linen tape be used in the housing's construction because fingerprints and wear will not be as obvious. Care should be taken that these housings be kept away from magnetic storage materials such as audio and video tapes and computers, because the Neodymium magnets may cause them damage.


Figure 11

Materials Suppliers:

Black rag board, 3M tape and black linen tape -

Mylar and Hahnemuhle-Ingres #114 black paper -

Neodymium magnets -


I would like to thank the Andrew W. Mellon foundation for funding the Collaborative Workshops in Photograph Conservation, Nora Kennedy, Debby Hess Norris, France Scully Osterman, Kelly Thielen, Jiuan-Jiuan Chen, Stacey VanDenburgh, Grant Romer, Mark Osterman, the Photographic Preservation and Collection Management Program with Ryerson University, and the Advanced Residency Program in Photograph Conservation, and last but not least Maryann Whitman and Tammie Malarich.

Papers presented in Topics in Photographic Preservation, Volume Twelve have not undergone a formal process of peer review.