Housing for an Oversized Map

[This blog post was written by Emily Rainwater, Conservator for the State Archives of North Carolina.]

The Mouzon Map and the housing created to protect it.

The Mouzon Map and the housing created to protect it.

An Accurate Map of North and South Carolina with their Indian Frontiers [M.C. 150.1775m], surveyed by Henry Mouzon II and known familiarly as The Mouzon Map, was published in 1775.  The map was utilized by American, British, and French forces during the American Revolutionary War.   It was printed in four separate plates, each with an overlapping edge designed to be adhered together into a single map. The State Archive of North Carolina owns two copies; one that is in its four separate pieces, and another that has been adhered to form a single map.

As you can imagine, a map that is made up of four already large pieces of paper is quite huge – 42 inches in height and over 56 inches in width! This is too big for even our largest map case drawer, so a customized, unique housing needed to be constructed when the map came down from display.

The housing had to meet several requirements:

  1. Constructed of archival quality materials that age well and will not contribute to the map’s deterioration
  2. Large enough for the map to lay flat as a whole piece, with some extra wiggle room for a protective border
  3. Allow for access to the map when needed
  4. Rigidity, allowing the map to be stored on top of the map case as it is too large for the drawers. Since a few inches of the housing will extend beyond the platform of the map case, the housing must be supportive enough for this function.

Diagram of the structure of the portfolio case constructed to house An Accurate Map of North and South Carolina with their Indian Frontiers [M.C. 150.1775m], also known as the The Mouzon Map.

Diagram of the structure of the portfolio case constructed to house “An Accurate Map of North and South Carolina with their Indian Frontiers” [M.C. 150.1775m], also known as the The Mouzon Map.

We decided on a rigid portfolio case with twill ties. The map itself was hinged to a piece of double wall, corrugated BB-flute board with long fiber tissue and wheat starch paste. These hinges keep the map from sliding around, but will also be easy and safe to remove if needed in the future. The double wall structure means the board is constructed of two layers of corrugations, making it very strong and rigid. A protective top layer of double wall corrugated board is laid directly on top of the map.

The outer components of the structure are two pieces of corrugated polypropylene board, known as Coroplast. Coroplast is chemically inert, will not off-gas, is extremely durable, and is made of archival grade plastic. Small cuts were made in the Coroplast so that cotton twill strapping could be threaded through each board. This strapping allows the two exterior pieces of the portfolio to be tied together, and secures the inner pieces of corrugated board.

Though size presented some challenges, this custom-built housing will continue to protect this object for many years to come.

The Mouzon Map portfolio case closed and tied.

The Mouzon Map portfolio case closed and tied.

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