Only "Unbuffered" acid free tissue should be used with textiles.
Buffered tissue with an alkaline reserve is not an appropriate material
for the archival storage of textiles.
I think, this generalization is not completely correct.
For cellulosic textiles (cotton and linen etc.) buffered paper is just
perfect, however silk and wool generally need even a slightly acidic pH
as their most stable environment.
The problem really is, that textiles, as well as many other kinds of
objects in mixed media collections (e.g. Historical Museums) rarely come
as pure cellulosics or pure animal fibres.
I think this really points toward a field of research desperately needed:
we do know about possible damage of using the "wrong" pH with certain
groups of pure materials. But: how do these dangers compare? Is it a
higher risk to store a linen fabric with silk embroidery and metal
thread in neutral, in slightly alkaline (buffered) or in slightly acidic
(nonbuffered, aged) paper?
Ideally a museum would have to stock three different types of tissue and
- as posted at the beginning of this thread - change it regularly.
However, experience in real life proves, that keeping track of the type
of paper is impossible (they all look nearly the same) and paper is
frequently "transferred" from one object to an other one when working
with the collection. Therefore, having three different types of paper
available and using them correctly is just not realistic, nor is the
idea of constantly walking around with a pH-testing pen (cost of
manpower!) The question asked above thus becomes even more urgent: what
type of paper will pose the least risk to the bulk of a mixed
collection? (Please note: I am not talking single objects, but collections)
I think the research needed would have to go into the kinetics of aging
fibres and the change in this kinetics by direct contact with the
different types of paper under museum environment conditions, and under
not quite as ideal climate conditions (church, basement, attic). And
there will have to be research into how long it will take under what
climate condition for the various types of paper in contact with
objects to change significantly (i.e. how long will the paper/ cardboard
box really provide the storage condition postulated?); this being a
ressource question (manpower, cost of material renewal).
With such research data, a calculated risk assessment would become
possible, and each museum / institution could adapt this risk assessment
to their specific collection composition. Such a risk assessment will
have to include a comparison of the multiple factors of risks and
benefits of the cellulosic storage materials to the risks and benefits
of other (manmade) materials.
All of this hopefully enabeling us to preserve our collections on a long
run with more and more restricted ressources.
Hoping somebody picks up on this idea....
Karin.
--
Karin von Lerber
Prevart GmbH
Oberseenerstr. 93
CH-8405 Winterthur
Tel. +41 (0)52-233 12 54
Fax. +41 (0)52-233 12 57
www.prevart.ch