The Clements Library website includes events, exhibits, subject guides, newsletter issues, library staff, and more.

Home » About » Blog » Conservation Close-up Part 2: Sea Charts used in Whaling

Clements Library Conservator Julie Fremuth provides a follow-up to our recent post about the arrival of 14 tightly-rolled sea charts and early conservation steps. The initial post Conservation Close-up: Sea Charts used in Whaling discusses Fremuth’s months-long process to safely and gradually flatten the maps. Generously donated to the Clements Library by Frederick and Janet Stingel, these charts were once used for navigation aboard whaling vessels.


This is a follow-up to a recent post which discussed the early conservation steps of fourteen tightly-rolled sea charts.

Five of the fourteen maps were smaller, in fair condition, and flattened more easily. These maps received edge repairs with Japanese paper strips and methyl cellulose. Japanese paper was chosen as it is a relatively thin, long fibered paper which provides incredible strength. Methyl cellulose was selected as the adhesive because it has a neutral pH and dries more quickly and with less penetration than wheat paste. These maps were cataloged, encapsulated, and stored flat in folders in the map drawer units.

The nine largest maps needed more flattening time and repair. Several of these maps sustained long tears from the edges. This was caused by the opposing tension in the paper, from people unrolling them when they had been stored tightly rolled for so long. Once the paper relaxed and the maps finally flattened, the tears were repaired. A heavier, blue tinted Japanese paper was used to consolidate the edges of each tear and add reinforcement from the back side.

Aside from the few edge tears, these maps were printed on good paper and now are in very usable condition. However, they are either too large or too long to be stored flat in the library’s map drawer units. In order to establish safe storage and housing, each map has been carefully rolled around the circumference of its own acid-free, 8-inch diameter tube, the ends of which securely rest on “U-shaped” inserts located inside the ends of its acid-free, fitted box. The “U-shaped” inserts prevent each rolled map from shifting or resting on itself. The 8-inch diameter tube provides a gradual arc and will not compromise the opening or use of these maps in the future. Each map is stored in its own box with an affixed label. The original wooden storage box will be saved and stored with them.

One very large map was in particularly rough condition. This map was shellacked and tightly rolled like the others. The shellac made the paper quite brittle. These conditions caused the map to crack and split into many fragments and pieces.

This map is too large to be stored flat, and we did not want to re-roll it, as the shellac has made the paper brittle and stiff. There is an existing crack across the middle of the map and we decided to separate the map into two halves and store them as two, individual pieces. 

Each map half and its fragments were lined with a supportive, blue-tinted Japanese paper and methyl cellulose. The two, separately lined halves of the map now can be stored flat.

The large and varying sizes of these maps as well as the amount of time needed to flatten them made the process a bit challenging. It is gratifying now to have the maps cataloged and in usable and accessible condition.

A glimpse of Conservator Julie Fremuth’s detailed notes from her long process of repairing this collection and preparing it for archival storage.

Collection of maps and charts donated by Frederick and Janet Stingel

View all 14 records in the U-M Library Catalog