Three messages on encapsulation procedures.---------Johnnie
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Fri, 04 Mar 94 11:19:28 CST
Donna Koepp <[log in to unmask]>
Encapsulation
My experience here at University of Kansas has been with encapsulating
the maps from the U.S. Congressional Serial Set. We deacidified the
maps before encapsulation using Wei T'O Soft Spray. We sealed the
Mylar with an ultrasonic welder, but even with this process we have
raw edges of mylar, because the Minter Ultrasonic Welder does not
seal the very edge, but a small distance in from the edge. We did
however, invest in a corner rounder, which I think is probably the
key to preventing damage to other non-encapsulated maps.
My recommendation for thickness of Mylar would be 5 mil, depending
upon the size of your map. With two pieces of paper between the
Mylar sheets, I think you would need this thickness. We used 3 mil
for the maps we have encapsulated here, but that was really pretty
thin for the largest of the maps. We did it just for expediency in
using the Minter Ultrasonic welder, which does not easily accomodate
the thicker Mylar.
Just from experience, I think you may find that the map will move around
within the envelope with two pieces of paper in there. The thing
that keeps the map stable is the static that builds up between the
mylar sheets, and you will lose that by having two sheets, which will
have some airspace between them. I think you will need to trim the
mylar very close to the map to hold the map in place. Then, of course,
you run the risk with tape, that the map may come into contact with
the adhesive.
My thoughts on the security strip, is that it should be on the side
of the acid free paper AWAY from the map. Those strips are highly
acidic, or so I have heard, and I think it would not be a good idea
to have it in contact with the map. If you are taping the edges of
the mylar, how about putting it along the edge as part of the tape
holding the mylar closed? Just a thought. Otherwise, could you put
it under a piece of tape on the acid free paper, and have that piece
of tape be your label, to somewhat disguise it?
Good luck. Sounds like a good project.
Donna Koepp
University of Kansas
Government Documents and Map Library
913 864 4660
DOCSMAP@UKANVM
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Fri, 4 Mar 94 10:32:13 HST
Ross Togashi <[log in to unmask]>
Re: Encapsulation
Greetings,
Regarding map encapsulation, this is how we do it over here.
1) We use 4mil on the majority of our encapsulation, but go to a heavier 5mil
if we feel that the map needs more support because it is large or poor shape,
and if it is an item that is frequently handled. We own a ultrasonic
encapsulating machine which is capable of sealing various thickness of
polyester and so, no longer use double-sided tape.
2) We do not tattle tape any of our maps. At the moment, our map collection
is a "closed-stacks" library with staff on hand whenever we are open to the
public.
3) I don't quite understand your fear about sharp edges of the polyester.
The only thing that has potential for damage is the corners, but we round
them off with a corner rounder (scissors will do fine) so that they do not
poke any other map or person. I've never thought about using single-sided
tape on the outside, but imagine that eventually the tape will either rub or
peel off. Also, there will be a problem of the tape being unable to flex
with the polyester, which might make the tape buckle and eventually come off.
If you haven't yet, I would recommend that you take a look at _Polyester Film
Encapsulation_, by the Library of Congress. SuDoc no. LC 1.2 P76. It shows
how to encapsulate and has good illustrations, showing step-by-step how to do
it.
Aloha,
Ross Togashi
University of Hawaii at Manoa
Hamilton Library Map Collection
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Fri, 04 Mar 94 09:21 PST
"Carlos B. Hagen-L" <[log in to unmask]>
Re: Encapsulation
Hello. My name is Eric Scott. I'm an L.A. at the UCLA Map Library. I handle
most of the preservation here--which is minimal, unfortunately.
Regarding encapsulations, we use 3 mil mylar which we obtain from Conservation
Resources in Alexandria, VA. We do not add a sheet of acid-free paper as this
is more expensive and makes the material being encapsulated so thick that the
map can move around. We use double sided tape and very neatly trim the mylar
to within about 1/8" of the tape and round the corners. We avoid exposing the
tape as the glue can stick to other maps within the folders. We've never had
a problem with the edges cutting or tearing other maps, only sharp corners seem
to be a problem. I use double-sided tattle tape and put it right along the
edge of the mylar in place of a section of the double-sided tape. I started
doing this myself--I haven't heard of anyone else doing it. I figure if anyone
is going to try to get out the tattle tape, they are going to destroy the encap
sulation. At that point, they would probably just try to cut the map out of
the mylar. We don't usually let our valuable maps out of our sight that long.
I would argue that, with maps, an obviously tattle taped item is discouraging
enough in itself for all but the most serious theives, etc.
I hope this info. is useful. If you would like to querry me further, you can
reach me via e-mail: ECZ5EDS.MVS.OAC.UCLA.EDU Or by phone (310) 825-3493
8am-5pm PST. Good luck!------Original message----------------------------
Eric Scott.
>
> We are considering encapsulating some of our more fragile and irreplacable
> maps. We are going to buy rolls of polyester, sandwich the map along with a
> piece of acid-free paper with tattle tape attached. I have a few questions
> about this process:
> 1. Is ther a recommended thickness of polyester that we should use?
> 2. Should we place the tattle tape between the map and the sheet of paper so
> that it is invissible to any user or, place it on the visable side of the
> acid-free sheet of paper away from the map but in plain sight? I guess we
> could cover it with tape, however, how hidden would it be?
> 3. We had thought to use the double sided tape companies sell along with the
> film, however, I have a concern with that. Does the use of double-sided tape
> leave sharp, polyester edges free to slice through other maps in the drawer?
> Does anyone use single-sided tape on the outside of the sandwich, putting
> tape on the front sheet of poly, folding the tape over the edge (therefore
> covering those sharp edges) and sticking the tape to the back sheet? Does
> anyone sew the sheets of polyester together? (You still have sharp edges, but
> the preservationists fear of adhesive is gone.)
> Thanks for your advise and assistance.
>
> Michael McDonnell
> Waldo Library
> Western Michigan University
> Kalamazoo, MI 49008
> 616 387-5208
> [log in to unmask]
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