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[Fwd: removal of bleeding dyes]



Dear Karin,

Could you please forward this onto the tex.cons dislist? The server
still rejects my messages, so I must rely on others.

It's a funny thing about dyes. In order to dye or print a fabric to
achieve a fast result, we must accurately follow the given procedures of
achieving certain temperatures, maintaining them for specific times and
adding additives at the right moment etc. Yet on the other hand, these
rules apparently do not apply to dye stains either from
accidental spills or bleeding. In these cases, the dye fixing seems to
be mostly instant and permanent! A classic case of Murphy's Law, I suppose.

Considering that the extraction of early synthetic dyes requires often
requires boiling (Schweppe's book on the ID of early synthetic dyes) and
that steam guns are used by dry cleaners, steam (using a steam gun) may
work but of course the heat would accelerate fibre degradation. Another
option is ultra sound which may well be less violent than heat (I am not
up to date on that). Rowenta has recently brought out an ultrasonic
stain remover for home use (60 euros) which looks as if it may be very
useful. It is meant to be used with an Ariel laundry detergent but such
marketing strategy should not get in the way of the resourceful textile
conservator. Perhaps you could get one for a free trial.

www.*rowenta*.fr/*rowenta*/detacheur_*ultrasons*.htm
There are other versions about. www.ultrasonic-stain-remover.com
<http://www.ultrasonic-stain-remover.com>/

There is also sunlight. This sounds very wicked but paper conservators
do sun bleaching without destroying objects. The effect is concentrated
on the surface (that is viewed) unlike reduction or oxidation treatments
which affect the whole substrate. With prolonged exposure as in being
displayed in sunlight for years on end, the degradation gradually 'eats'
deeper into the fibres.  You can see this on faded early synthetic dyed
wool yarns where the surface fibres are badly faded but the middle
fibres are still brightly coloured. The total resulting fibre
degradation from a controlled sun bleaching treatment (blocking off the
unstained areas of course) may actually be less than a conservation
chemical bleaching treatment.

Should the stains still remain, there is always the consolation that
being affected by this 'historical' flooding (as opposed to an
overflowing gutter) is a chapter in the history of these textiles. In
fact, one could perhaps argue that the stains should not removed at all.
In that case, only the 'loose' bled dye should be removed as it most
probably would readily bleed again if affected by moisture and as such
would pose a definite risk in the event of future water damage.

The more I think about it, the more it seems necessary to consider this
aspect of historical context.
Do all these textiles have such a function in the collection that they
must look as perfect as possible?
Is the expected result really worth all the time/money required of tests
and treatment and the risks involved?
Should these aspects be already considered then ignore the above!

In any case, it is a valuable learning opportunity and I hope you can
find the time later to publish your findings, not forgetting the
protocol you developed for testing.

Here is a treatment which may work in some cases. I heard that it was
developed in consultation with paper conservators so you could consult
them as well for more ideas.

best wishes and good luck,

Jennifer

Jennifer Barnett
Regina Textilia
historic textiles conservation, research and consultancy
La Goute, route de Dancé
FR - 42260 Bully
tel/fax * 33 (0)4 77 65 20 11
reginatextilia@xxxxxxxxxx <mailto:reginatextilia@xxxxxxxxxx>



Iso-propyl alcohol treatment for indigocarmine dyed textiles.

--
Karin von Lerber
Prevart GmbH
Oberseenerstr. 93
CH-8405 Winterthur
Tel. +41 (0)52-233 12 54
Fax. +41 (0)52-233 12 57
e-mail: karin.vonlerber@xxxxxxxxxx
www.prevart.ch

Attachment: Isopropyl alc treatment.doc
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Attachment: Isopropyl alc treatment.doc
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Indigo-carmine is also known as Saxon Blue. It has been produced from indigo and sulphuric acid since 1740.

There are 2 articles in Dutch about the problem, both from 'Indigo', 1988, Textielcommissie Musea;

Roelofs en Hofenk de Graaf, 'Een uitbloedende kleurstof.'(A bleeding dyestuff)
van Nes, 'Een methode tot het verwijderen van uitgelopen indigocarmijn in borduursels'.(A method for the removal of indigo carmine stains on embroideries. 

One of the cited references is also of interest;
Duff, Sinclair, Stirling (1977), 'The fastness of some natural dyestuffs on wool', Studies in Conservation, 22, pp 170 - 176.

I have had experience with two samplers with blue/green silk yarn which ran immediately in all 3 test solutions and also water. This reaction is apparently typical for indigocarmine (the dyestuff was not positively identified). The treatment described below, from the van Nes article, was followed with success.
A sampler with unstable brown silk thread was also successfully treated in the same way.


Treatment

Tests required; usual colour fastness test plus fastness to iso-propyl alcohol.

1 Wash and rinse textile. Lay it on a blotting cloth to remove excess water. Do not blot with an overlay - this will remove dyestuff.

2 Prepare 3 trays with a shallow level of iso-propyl alcohol and set them in the fume cupboard. Use rubber gloves for handling the textile and avoid breathing the fumes.

3 Lay the textile for a few seconds in each tray. 
(At first there was a dramatic outsurge of colour as the iso-propyl alcohol evacuates the water and its dissolved dyestuff from the textile. This decreased with every successive rinse bath). 

4 Lay the textile face down on a blotting cloth. Allow to dry in the fume cupboard or on a vacuum table. Iso-propyl alcohol is polar enough to make pinning out worthwhile (if neceaasry to control the shape) it was found.


Risks!!
Loss of colour intensity due to loss of indigocarmine during the washing process.
Washfast dyestuffs may bleed in iso-propyl alcohol.
Iso-propyl alcohol is a hazardous solvent for humans.


J.C.Barnett, 13 March 1998








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