Lining tapa

Ivonne Geisler <geisler.ivonne [at] gmx__de> writes

>I am working at a painted tapa from Fiji. This has to be lined.
>Unfortunately water causes stains. Does anyone has experiences with
>synthetic resins onto tapa?

In order to find a solution,  you have to deal with several
different problems at the same time.  I can't give you a final
answer, but can try to get closer to the nut of the problem. (This,
of course, all depends on the "typical" tapa that I see in my head
when I read your posting!).  The  main issues are conformity of the
lining to the ripples of the tapa, the texture of the lining, and
the one you mention--the sensitivity of the paint to solvents.

The latter can be overcome by using a heat-seal adhesive, but that
leaves the others!

I often use polyester "net" or cotton fabric sprayed with polyvinyl
acetate resins as a heat-seal adhesive for the lining of textiles.
(P. Himmelstein,  B. Appelbaum, "The Use of sprayed polyvinyl
acetate resin mixtures in the mounting of textiles," AIC Journal 17
(1977): 37-44.) It has tremendous advantages in terms of
manipulating shredded, ripped, and other-wise messed up
textiles--but  a non-penetrating lining won't, of course, deal with
interlayer separations.)

The major problem is the ability--or lack thereof--of the backing to
conform to the ripples of the original, which could be a big problem
for tapa.  For thick embroideries, one can cut the lining at just
the right places on the reverse to allow the net to ease around
lumps; this sort of thing might be applicable to your problem
depending on its thickness and unevenness. Otherwise you can end up
with bubbles between the lining and original  where the lining
doesn't conform. I have tested knitted nets as supports, but at
losses where the net shows through, the knitted texture looks
peculiar.

Which brings up the other problem of using woven textiles for lining
tapa.  I have seen on at least one occasion a tapa that was
heat-seal mounted with nylon net, and in raking light you could see
the outlines of the chicken-wire type weave.  However, nylon threads
are tough--it may be possible to find a cotton net that has softer
fibers and doesn't imprint.  For textural purposes, paper or
possibly a textile nonwoven might do.  Some types of nonwovens have
much more "give" than paper, but some have very difficult handling
properties.

Back to the ripple problem.  When you use an aqueous adhesive with a
paper lining, the paper is softened enough so that it conforms -
paintings conservators do this all the time with facings using
wet-strength paper.  Using small overlapping pieces of thin net and
a tacking iron in uneven areas might help.  It might be possible to
shape paper with water using thin mylar between the two and then let
the paper dry--it's a cute idea, but maybe not doable.

Obviously this all depends on the details of the object and its
future use--does it need overall lining for strength?  Are you
trying to make it flat for display?  Etc.

(I realized from a rereading of your posting that the staining may
not be from the colorants.  Is it possible that the stains are brown
lines from chemical changes along the drying line of  the water or
related to the movement of water-soluble dirt?  I suggest you look
up an article I can't put my finger on at the moment on "tide lines"
in textiles.  There may be a way around this whole problem that
involves controlling the evaporation of water.)

I would be curious to hear more about this treatment--it is an
interesting cross-disciplinary problem that benefits from a lot of
different points of view.

B. Appelbaum
Appelbaum and Himmelstein
444 Central Park West
New York, NY  10025
212-666-4630
Fax: 212-316-1039


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                  Conservation DistList Instance 18:49
                 Distributed: Thursday, April 14, 2005
                       Message Id: cdl-18-49-001
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