-------- Original Message --------
Subject: Re: Storing historical maps on large diameter tubes
Date: Tue, 30 Mar 2010 12:01:24 -0400
From: Edward James Redmond <[log in to unmask]>
To: Air Photo GIS Forum - Map Librarianship Maps <[log in to unmask]>
References: <[log in to unmask]>
Ms. Baker:
In response to an earlier similar question I asked the advice of the
our conservators here at the Library of Congress and they provided the
following information:
"Our conservation staff who specialize in oversized materials,
including maps and posters, have sent me the following information. The
first part below comes from our map conservator, and the second part is
form our poster conservator.
Maps:
1.) vertical storage is only being considered for either "framed" maps
(i.e., G&M chose not to remove from frames after exhibition), or maps
that exceeded the size of the drawers and are in custom made portfolios
(made from acid-free corrugated double-walled board). Any map that is
stored vertically must be fully supported.
2.) rolled storage is limited to maps that were made to be rolled and
where issued with wood dowels at each end. We unroll the maps, place a
sheet of 5 ml Mylar on both sides of the map and roll it back up
creating a roll that is not tight, but at least 4 - 5 inches in
diameter. The rolled maps are placed in long polyethylene bags for
protection. The more valuable over-sized maps are stored on huge tubes
(12 inches - 18 in diameter) that vary in size according to the size and
condition of the map (media and paper support).
Posters:
The Prints and Photographs division holds approximately 11,000 posters,
most of which are encapsulated between polyester film with buffered
paper against the poster verso. Posters too large to fit into flat files
are either hung on racks or rolled onto tubes. We have long been trying
to replace the vertical system with custom made oversized flat files,
and would ultimately like to store the rolled items in oversized files
as well.
The rolled posters are placed onto wide-diameter, acid free tubes and
covered with acid-free paper and polyester film to protect against
light, dust and moisture. The tubes are then supported above the surface
with cradles placed on either side of the tube, beyond the edge of the
poster. This method makes it very time-consuming to view the poster.
Furthermore, posters may, over time, develop a strong curl that cannot
be relaxed without treatment using humidity. This is particularly a
problem with posters that are lined onto Japanese paper. Furthermore,
rolling places a lot of stress on areas of damage such as tears, and can
cause fragments to loosen and become lost.
The vertical system was designed in the early 1980s or late 70's. The
posters are encapsulated in clear polyester film that is heat-sealed
along the edges. The posters are held within the encapsulation by a weld
(made with an ultrasonic welder) across hinges attached with paste to
the top edge of the poster. The poster is suspended from wooden hanging
racks using metal hangers (made for hanging a shower curtain) inserted
into grommets affixed along the top edge of the encapsulation. Methods
for hinging and hanging the posters have been modified over the years to
address problems with the posters slumping inside the encapsulation over
time. We have experimented with different types of hinging mechanisms
and placed rigid acid-free board behind the poster to provide extra
support inside the encapsulation. A major problem has been with very
long posters that are greater in height than the hanging furniture.
These posters are "draped" inside their encapsulation using successive
rows of hangers, eventually causing the polyester seal to weaken and
possibly open. This is also quite inefficient in terms of space usage.
I believe a custom-designed oversized flat file will hold more items
and in a more safe manner than a vertical storage system.
If you would like more information, you might want to consult
“Storage Solutions for Large. Format Works on Paper” by Michelle
Facini, published in: Rayner, Judith, Joanna M. Kosek and Birthe
Christensen, ed. "Art on Paper: Mounting and Housing." London:
Archetype, 2005. ISBN 1-873132-99-9; http://www.archetype.co.uk "
Ed Redmond
Geography & Map Reference Specialist
Geography and Map Division
Library of Congress
101 Independence Ave, SE
Washington, DC 20540-4651
(202) 707-8548
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-------------------------------------------
The views expressed in this message are solely mine
and do not necessarily represent those of the Library of Congress.
>>> Angie Cope <[log in to unmask]> Tuesday, March 30, 2010 11:26 AM >>>
-------- Original Message --------
Subject: Storing historical maps on large diameter tubes
Date: Tue, 30 Mar 2010 11:10:43 -0400
From: Amy E Baker <[log in to unmask]>
To: [log in to unmask]
How do you store large historical maps that require a large diameter
core? What materials do you use for a core or tube?
I am a conservator at an academic library, and we have about 35 large
maps that require permanent archival storage on large diameter tubes
(10
in. x 6 ft.) We've been quoted $170 for one acid-free tube this size.
Although we have a decent budget I can't justify to myself spending
$6000 on this...There are many solutions out there that involve
wrapping
a non-archival material in something else. Examples are PVC pipe,
bubble
wrap or cardboard cement forming tubes covered in bookcloth, mylar,
muslin or polyester webbing.
What solutions have you come up with at your institution? How are the
cores holding up?
Thank you. Your suggestions are much appreciated.
Amy Baker
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