Washing antique textiles

Please keep in mind that any wet process is a harsh torture and potential damage for each fiber. They are made to stay dry. The most sensible part of a weave are the dye lakes 1 (as opposite to vat dyes et.al.).

In order to understand the basic problem of antique washing please imagine the following situation: in a wild, big garden, forgotten since long time, there is a wall made from bricks. The bricks are spotty. Lichens grown on them, even mosses. Residues of evaporated salt is visible on the surface of the bricks. The mortar, that once kept the bricks together, is corroded. A certain part of the mortar has fallen down. If one scratches some spots, where the mortar seems to be intact, it is easily removed.

In case one would try to clean this wall by means of a high pressure - hot water cleaning apparatus for sure some parts of this wall would be clean. Some parts would be smashed under the high pressure. Even where the mortar seems to be intact , but is in fact partly corroded though invisible, it would be rinsed out. As a consequence quite a lot of the bricks would drop out of their context, immediately or later. Therefore some parts of the wall most likely would collapse.

It would have been bettr first to remove the corroded mortar and replace it immediately by fresh one. Some days later this fresh mortar would be hard and resistant. Then it would be possible to clean the whole wall thoroughly. It would be kept intact and would look moreor less clean, then. That it is an old wall would remain perceptible.

Antique textiles should be cleaned according to this principle. They have been made using mortar. Substances that can be compared with the mortar of this above given example exist in deed:

  • the keratin molecules of wool fibers, the fibroin of silk and the cellulose molecules2 of cotton or linen are oxidized by light
  • the chemically heterogenic set of substances that we call „wool fat" is
    changed by light oxidation, dust, washing and by chemical attacks.
    Its amount is decreased, the wool gets dry, unelastic and brittle .
  • substances, which are part of the dye lakes, are attacked by
    oxidation and are constantly removed. The dye appears to be less
    vivid, sometimes even spotty.

The first step of treatment should be to repair the damages caused by oxidation, but they cannot be completely reverted. This result of us is confirmed by a new research reports on how to treat microbials stains on antique papers 4 . Then the dye lakes must be repaired.

After this is done the textile can be washed. Preferably „soft" type of tensides (detergents) should be applied. Alkyl sulphates or even alkyl ether sulfates must be avoided because of their strong defattening properties. Certain tensides tend to form chelates with polyvalent metals (all ethylen oxide adducts). They attack the fastness of dye lakes and should not be used therefore.

Against common knowledge soap is not an adequate tensid to wash antique textiles made from wool. To achieve a proper cleaning action with soap the fluid must be quite alcaline. Wool absorbs acids and alcaline substances strongly. They cannot be removed with cold water and remain in the wool causing long term damage. The optimal pH for wool and for human skin is pH 5,5.

Finally the textile should get a refatterning treatment using exclusively natural substances. This claim excludes lanoline with is manufactured using mineral oil based waxes. Under no circumstances one may use synthetic substances in order to improve the lustre. Many of them adhere irreversibly as it is the case with the new synthetic silicone substances.

If one is limited to use exclusively natural substances for refattening the consequence is an antique textile with a good lustre of excellent dyes and wool but with a lackluster sheen where their quality would be mediocre. If silicone is applied a stark glare dominates all areas of this textile. But silicone adds this glare even to grey concrete.

It is said that an archaeological excavation is the only scientific experiment that cannot be repeated. The same is true for washing antique textiles, especially if they have been stapled somehow somewhere in the Orient. In case they are submersed in a first step into soft water and in case they are washed using a special soft tenside nevertheless all dyes, which are not fixed good enough by means of the above mentioned processes,are irreversibly removed. Perhaps the textile would be clean then. Regarded as a piece of art it is heavily damaged, if not destructed.

On request we are ready to communicate which textiles, whose condition before and after such treatments we could check with our own eyes, have been „improved" by this way in the last years.

For a critical evaluation it must be noted that one has to achieve a balance between factors that may oppose each other when an antique wash is done3 :

  • to remove dirt
  • to restore the vividness and fastness of the dyes
  • to improve the long term durability of the textile by regaining its elasticity

The system used here puts the priority on the last two aims, in case of conflict on the expense of the first one.

1 A state of the art treatment of an 18th century "Konya" carpet with an open, bright, lucent yellow would be like this: first a HPLC with Diode-Array-Detection analysis of the dye, whether it is made up from (a) flavones or (b) flavanol-glucosides. In case (b) under no circumstances even 1 drop of water should be applied: the bright yellow would change irreversibly to a dark, matt ochre-brown- yellow - as is has happened often in the last 15 years.

2 In fact there are more different molecules in cotton and linen than just cellulose.

3 Attention: in case a C14-radiocarbon dating is planned the natural auxilliaries used here may interfere with that. The result would be too „young" then.

4 Koch, Beate, Trick, Iris & Vohrer, Uwe (2000): Stopp dem Buchzerfall. Spektrum der Wissenschaft, 4 , 2000, 85 - 87. - This is the latest high technology approach for paper conservation. Realized with different tools this is exactly the same kind of treatment that KÖK uses since about 15 years for securing antique textiles.

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