NOTES FROM PRESERVATION
Adhesive Binding or 'Tar-Pit Dinosaurs"
The principles and methods of adhesive binding are as simple as dino-
saurs falling into a tar-pit. There is nothing exciting about adhesive bind-
ing. "You can bind any old thing if you've got something sticky." In theory,
adhesive binding is like tipping one page atop another page until all the
pages of a book are tipped together. The only exception to this singular
method is the "bursted binding" for which adhesive is used to bind folded
sheets. An adhesive binding is a binding in which adhesive is the only
thing holding pages together.
An adhesive binding is only as good as the adhesive. Right? Well, not
exactly. That would be like saying a dinosaur-filled tar-pit is only as good
as the tar. I suppose a strong or smart dinosaur could have freed itself from
the tar-pit. The quality of an adhesive binding is dependent upon the pa-
per and the adhesive, as well as the manner in which the adhesive is ap-
plied. Brittle paper may leave a bit of itself behind in order to break free.
Brittle paper defies binding like the disembodied hand in the Mexican
horror movie, The Hand, defied hand-cuffing. Similarly, coated- (i.e.,
"glossy') paper may slip out of its coating to freedom like Harry Houdini
out of his straight-jacket. Coated-paper has to be roughed up a bit, to ex-
pose the paper beneath the coating, before it can be bound.
continued on next page 0
Then, there's the adhesive. Two types of adhesives have been used to'
bind books in the modem age: animal glues and synthetic glues. Animal
glues tend to discolor and embrittle with age. Of synthetic glues, some dis-
color and embrittle, others become rubbery and shrink, and still others re-
main stable and flexible with age. Elmers' Gluer" embrittles, loosing its
flexibility. Brittle glues allow bindings to break, spines to crack and pages
to become detached. A book with inferior glue whether animal glue,
Elmers' or another synthetic glue must be rebound. Poly (vinyl-acetate)
(i.e., PVA) glues such as ElvaceTM and JaderM are acceptable for binding.
Unfortunately, it will not be easy to tell if your book has been bound with an
acceptable PVA. As a general rule, thickly applied glues thicker than
0.25mm are likely to be unacceptable. If you can't afford to rebind your
adhesive bound books, use them as carefully as you can. Cracking the spine
of a book to make it more readable is false economy unless you can afford to
throw the book away. You wouldn't break a dinosaur's back to free it from a
tar-pit, would you!
Finally, there are application methods to consider. This is akin to dis-
cussing how dinosaurs fell into tar-pits in the first place. If they fell off
cliffs into a tar-pit, there may well have been no way out. But if they wad-
ed in, perhaps they could waddle out. Likewise, if adhesive touches the
book-paper only in a few places, as it does with bursted-bindings, it won't
be strong enough to hold the book together. Further, if adhesive doesn't
grab hold of the paper's fibers, it won't matter if it touches the book-paper
"all-along" or not; it will not hold over time. There are three basic meth-
.ods of application: "perfect binding," "Mekanotch binding," and "double-
fanned adhesive binding.".
When perfect binding, a book is placed in a press and glue is applied to
the spine. The method is so named because the spine is perfectly flat or
flush. Of the three methods, perfect binding has the least surface contact
with the book-paper. Mekanotch binding, a perfected form of "perfect
binding," makes notches in the spine of the book which allow for more sur-
face contact with the book-paper. It is also argued that the notches allow
PVA to settle and form "cords" in them which support the binding just as
linen cords do in traditional binding, When double-fanned adhesive bind-
ing, a book is also placed in a press. Its pages, however, are fanned out in
one direction, then the other as glue is applied. This exposes a bit of the
gutter margin and effectively tips each page, back and front, to the pages
next to it. This method is also sometimes called "perfect" though close ex-
amination shows slight swelling at the spine caused by the introduction of
glue between the pages. Double-fanned adhesive binding is the strongest of
the three methods and has the most surface contact with the book-paper.
This method is sometimes combined with Mekanotch binding, again, to al-
low PVA cords to form in the notches. I tend to think that this places undue
stress on both the PVA and book-paper as the book opens and closes. Person-
ally, it seems to me that this is like putting a leash around your dinosaur's
neck and going out for a walk just beware the tar-pits!
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