Excel binding

Recently I had the opportunity to inspect several Excel bindings (about
which another library has concerns), and noted the following problems:

1.  Double-fan adhesive bound volumes have one spine lining instead of
the two specified in the LBI Standard.  The single lining does not seem
to provide adequate support for serial volumes .  The lining is
sometimes a high thread count, but thin, cloth and sometimes simply
spun polyester.  (Spun polyester is the material that is specified in
the LBI Standard for the first of the two linings required for
double-fan adhesive bound volumes.)  Both materials have poor
dimensional stability;  spun polyester has very little tear resistance.
Text blocks are wobbly and fall forward in their cases like worn phone
books, spines concave and fore edges convex.  In some instances the
block actually protrudes beyond the case at the fore edge.

2.  Volumes that are sewn through the fold and lined with the thin cloth
also fall forward in their cases because of inadequate spine lining.
(The LBI Standard specifies that "all volumes over 1-1/2 inches thick
that have been sewn through the fold...shall be reinforced with an
additional layer of material"--either paper or a second cloth lining.)
None of the sewn-through-the-fold volumes are double-lined, which seems
to contribute to their instability.

3.  While the spun polyester seems to adhere firmly to the spines of
text blocks, the thin cloth appears to have a tendency to pull away,
sometimes leaving text blocks completely without the benefit of a
lining.

4.  Because the wide hinges are made up only of a layer of buckram, a
thin lining, and a paper endsheet, they are quite flexible.  In worst
cases (where volumes have obviously received some use) hinges have
become weak enough to fold back on themselves--again, causing text
blocks to protrude beyond their cases at the fore edge.

5.  Because text blocks are neither notched nor double-lined, instead of
opening in an arc, they open so that the backs of the two parts of the
block actually touch. Sometimes splitting can be observed along the
gutter margin, because of stress (I assume).  The spines of the cases
become so badly contorted when the volumes are opened that they develop
a permanent lengthwise crease, head to tail.

I need some help putting this situation into perspective.  Have I seen a
few problematic volumes culled from many that are better constructed?
How are Excel bindings (volumes that are double-fan adhesive bound,
unnotched, single-lined, flat-backed, and having wide hinges) aging in
the stacks?  Hope you'll take the time to respond.  The industry is
currently at a crossroads on this issue.

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                  Conservation DistList Instance 4:51
                  Distributed: Sunday, March 31, 1991
                        Message Id: cdl-4-51-002
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