How to preserve glass painting?

Repairing an old Chinese scroll painting [thanka]

• The Buddhist Institute of South Africa [www.brcixopo.co.za] has been given a beautiful Chinese thanka showing Sakyamuni Buddha in teaching mudra for display in its meditation hall at the Buddhist Retreat Centre in Ixopo, KwaZulu-Natal, South Africa. It is about 250 years old, 240 cm tall and 90 cm wide, painted in subdued colours on silk with the brocade and silk surround somewhat trimmed on all sides. It is mounted on a particle board and has been framed but has no glass in front. It has collected a gentle layer of dirt over time and has numerous small slivers of paint curled loose. This delamination was not helped by the previous ower who tried to "preserve" the painting by spraying an area with fixative..... Fortunately, this is only a small area: approx. 70cm wide x 25 cm high. I restored some Tibetan thankas 30 years ago and was advised to use a solution of polyvinyl acetate and toluene [I seem to remember??]which did preserve those paintings well. However, these Tibetan paintings did not show any breaking up of the paint from its linen backing such as has happened with this Chinese thanka which has been painted on silk. A Tibetan lama advised me to clean Tibetan thankas with bread crumbs which are rolled onto the painted surface, thereby picking up the dirt. It worked well, but I am afraid this method may lift off the loose bits of paint on the Chinese thanka. On the other hand if I sealed the paint first to secure it to its backing, I will probably seal in the dirt as well. Should I leave the cleaning well alone? This may be preferable to loosening the paint further! Is there anyone out there who can help us? As a religious organisation we cannot offer too much payment for suggestions on how to restore the thanka - we rely on donations to pay our way. Also, our South African currency comes at 10 Rand to the Dollar. So I hope someone knowledgeable is prepared to respond to this cry for help at a payment of 25 Dollars [250 Rand] Looking forward to any responses!!

• Answer:

  Hello there I hope you are considering a form of conservation that does not entail a complete restoration. There has been a change of heart within the archaeological/textile conservation community during the past several years. At one time full reconstruction was the norm, today scholars and collectors may prefer to see the piece in its current condition. That way they know what exists of the original workmanship. Faded color, flaws, loosened pigments, and other blemishes are acceptable and even welcome evidence of antiquity. Another reason to use extreme caution is that repairing a damaged textile by poor or incorrect work may effect the fabric's long term preservation. This can be avoided in a museum type situation where the item is needed only for display in controlled conditions. But if the thanka will suffer much handling, then some compromise is needed. I don't know how you go about taking care of such items within your Theravada tradition, but I am Jodo Shinsu and within our practice, sooner or later, the kids get their hands on just about everything in the temple. Forgive me if I sound as though I'm starting this at a very basic level, but since I don't have any real idea as to what you already know other than what you have mentioned in the question, it is probably safer. The care of antique textiles has three main features or phases - cleaning, restoration and conservation. The cleaning of antique textiles is a very complex process. If the dyes are safe, the textile may be washed in de-ionised water. Otherwise, chemicals similar to those used in the dry cleaning process can be used. But there is something else to consider when making your decision as to whether to clean the thanka or not. Signs of wear and dirt may offer crucial clues to the historic use of a textile, and act as a vital witness to its authenticity. This last feature may be of critical importance if you are considering having the thanka insured. Bits of pollen and other debris found in the layer of "gentle dirt" which can be identified with specific locations and seasons will go far in establishing value and history. If you do decide to go ahead and clean the piece, try to preserve some of this dirt and dust in case it is needed for future study. Here is a full treatment for the cleaning and conservation of a silk painting which has delamination problems. To do it properly, you will need to find a facility which has a vacuum table you may use. If you cannot find a vacuum table, you can still do the pigment consolidation I describe using a highly absorbant material such as layers of linen beneath the silk, though the work is much more exacting. I have worked with a vacuum table and absorbant padding both in the process of cleaning ancient painted fabrics. Remove the painting from its board mounting. Clean the surface of the painting with a very soft brush to remove loose dirt then place painting face up on the vacuum table. Roll lightly moistened cotton swabs very gently over the painting to loosen and remove soil. When doing this to an area of the painting where the pigment is loose, exert a straight down, but gentle pressure rather than a side to side movement. With a little practice, this can be done while still giving the swab a 'rolling' motion. Take great care was taken not to disturb pigments on the surface. A vacuum table draws excess water through the silk without damaging the delicate silk fiber. This process removes the stains and dirt but does not endanger the pigments. This process takes many hours of careful cleaning, the pigments will appear brighter and the surface of the painting looks better in general. Next, you will want to consolidate those loose pigments. It seems as though that in one of your main concerns. Use a traditional animal glue binder. Dissolve the glue in warm water to a 1 percent solution and apply with a brush. In similar work I have done with painted Egyptian linen (from the Coptic Period) I did away with the soft brush and used an air brush to lightly spray the glue. I would recommend this for your application. This process takes quite some time and needs to be repeated in areas needing better adhesion. The vacuum table's suction will pull the animal glue binder through the layer of pigments and into contact with the silk support beneath, ensuring stable consolidation and the pigments are no longer in any danger of coming off the surface when the thanka is handled. I stress the importance of taking a lot of time to do the job right. At this website from the Smithsonian points out - "A 14th-century Buddhist silk wall hanging with a royal blue background lies facedown on a worktable, where an expert using tweezers will take an entire day to remove one deteriorated square inch of the painting." - ( http://www.smithsonianmag.si.edu/smithsonian/issues01/nov01/mall.html ) - scroll about half way down to page. I am not including this because there is any additional information about preserving silk paintings, but to give emphatic reminder of the need for care. For some additional information about maintaining silk paintings "Maintenance of East Asian Painting" - ( http://aic.stanford.edu/conspec/bpg/annual/v12/bp12-09.html ) Covers both silk and paper conservation. Search was Google but most of the answer from personal experience and training. Key words - archaeological fabric conservation, conserving silk paintings, silk restoration and it was amazing how little there was to find My best advice is to do nothing unless the painting is so bad it cannot be seen or is terribly discolored. If you need further clarification or additional information, please let me know. Namu Amida Butsu digsalot