Here at BYU we used a sonic welder in the past, but found that the welds didn’t hold up to years of flexing between the layers of map and Mylar very well.  About 15 years ago we purchased another sealer that heats up and melts the edge of the Mylar, and we’ve used it exclusively ever since.  We too will seal the map on all 4 sides so that patrons aren’t tempted to remove the map.  But we do leave a gap on one side open for off gassing.  Some archivists don’t think this technique of dealing with off gassing is effective.  But we do it anyway.  We also leave enough room around the edges of the Mylar so that if a patron doesn’t like the quality of the scan inside the Mylar, we can cut 2 edges, pull the map, scan it, and have enough material to reseal again.



Hope this helps.

Rick Grapes

BYU Map Collection





From: Maps-L: Map Librarians etc. [mailto:[log in to unmask]] On Behalf Of Ryan Mattke

Sent: Monday, January 05, 2015 12:31 PM

To: [log in to unmask]

Subject: Map Encapsulating -- Best Practices?



Hello All,



We were recently fortunate enough to fund the purchase of a polyester sealer for use in encapsulating maps.



Previously we would encapsulate the maps and use double-sided tape to seal the edges, leaving some gaps in the sealed edges.



I'm wondering if there are best practices out there for using the polyester sealing machine -- for example, using a folded piece of mylar polyester, do you seal all three open edges or just two? Any other best practices thoughts would be useful as well...



Best Regards,

Ryan Mattke



--

Ryan Mattke

Head, John R. Borchert Map Library

University of Minnesota

S-76 Wilson Library

309 19th Ave South

Minneapolis, MN 55455



Phone: 612.624.5757

Email: [log in to unmask]<mailto:[log in to unmask]>

Web: http://www.lib.umn.edu/borchert<https://www.lib.umn.edu/borchert>