[NHCOLL-L:794] Re: glue and annotations

[Caleb Morse]

I know nothing about glue chemistry. That said, I do know that there is a
considerable amount of work in the art conservation literature about
adhesives and consolidants. You might look at old issues of the journal
Studies in Conservation. An oft-cited title in papers on adhesives and
consolidants is VL Horie (1992) "Polymers in conservation".

Until recently, we (KANU) were using "Yes" paste, to affix both specimen and
annotation labels. "Yes" paste is advertised as archival by at least one
reputable dealer in book preservation-related products. However, earlier
this year I ran across some posts on an art conservationists' list serve
that warn that (at least earlier formulations of) this paste have yellowed
(= acidified?) within a dozen years. Alarmed, I discussed this issue with
the book conservator and preservation librarian here at KU, and they agreed
that I should probably avoid "Yes" paste. Like most smaller herbaria, KANU
employs an overall gluing technique for mounting our specimens. My friends
in the library suggested I find a high quality PVA resin and use this for
securing both the specimens themselves and their labels. They recommended
PVA resin formulation R896A, marketed by Wisdom Adhesives (847-678-7750). I
have used this product and found it's quite easy to work with; we'll see how
it ages.

My friends in the library did suggest that other vegetable-based adhesives
(eg, wheat starch paste) might be also be employed for securing the labels.
Pastes are pretty easy to work with, but may not have particularly good
adhesive properties. I have seen labels affixed with various kinds of
adhesives (glue sticks among them) that have had relatively poor adhesive
properties and have become unattached from their sheet over time. PVA resin
may acidify slightly with time, but I don't think it suffers from that
problem.

On a related topic, the conservator took one look at the self-adhesive
barcodes KANU has affixed to some 350 000 sheets and said she'd bet they
would all be falling off within 20 years' time. The preservation librarian
disagreed, but it still has me worrying. The barcodes were purchased well
before my arrival on the scene. They are said by the manufacturer (Intermec)
to be "permanent," but what that means, I do not know and they could not
tell me.

I'll be interested to see what others who know more about this subject have
to say! Thanks, Rich.

Caleb Morse


----- Original Message -----
From: "Richard Rabeler" <rabeler at umich.edu>
To: <nhcoll-l at lists.yale.edu>
Sent: Wednesday, November 29, 2000 12:16 PM
Subject: [NHCOLL-L:792] glue and annotations


> When I recently read the "Conditions" statement which arrived recently
with
> a loan from the Royal Botanical Gardens at Kew for one of our researchers,
I
> noted the following item:
>
> "11. Please note that most office products (e.g., 'Copydex', 'Pritt' and
> other glue sticks, 'Sellotape' and 'Tipp-Ex') are not of archival quality
> and should not be used.  If you have doubts about the quality of glue
> available, please use paper clips to attach annotation labels to the
> herbarium sheets."
>
> While we use an archival paste for the specimen labels affixed by our
plant
> mounters, most of those folks affixing annotation labels are using an
> admittedly more convenient glue stick.  We are using a UHU stick.  I don't
> know much about the composition of the glue beyond the words "acid free"
on
> the side of the tube; no help at their web site.
>
> I did find a Scotch Glue Stick in a catalog of a company which focusses on
> archival-quality paper conservation items.  The glue stick is described as
> "permanent" and "acid-free" with a stated ph of 12.
>
> My question to other herbarium folks is two-fold.
>
> 1. What are you using for affixing annotation labels and
>
> 2. Have you come across any information that could "settle" the glue stick
> question?
>
> Thanks for considering my query.
>
> Sincerely,
>
> Rich Rabeler
> Collections Manager, Vascular Plants
> University of Michigan Herbarium
> rabeler at umich.edu