Encapsulation

Can anyone provide us with specific instructions - written and/or
diagrams - for encapsulating an entire folio or double-page spread from
a book, without cutting it in half and encapsulating it as two separate
sheets, when making a Mylar book.  Any advice or accounts of experience
or references to existing descriptions will be greatly appreciated.
Thank you!

Joan ten Hoor, Preservation Librarian, Newberry Library
60 W. Walton St., Chicago IL 60610 (312)943-9090x440
E-Mail: 76636.3506 [at] CompuServe__COM    Fax: (312)266-6039

    **** Moderator's comments:   Joan wrote back to add "We have a
    Minter ultrasonic welder.  We are interested specifically in
    techniques for single bifolia right now, but any info on nested
    bifolia might come in handy.  We are embarking on a project to
    format some of our county atlases as Mylar books.  Many of these
    have maps and illustrations that take up a bifolium.

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                  Conservation DistList Instance 4:45
                Distributed: Saturday, February 23, 1991
                        Message Id: cdl-4-45-005
                                  ***