Excerpted from Sacred Visions: Early Paintings from Central Tibet,
by Steven M. Kossak and Jane Casey Singer, with an essay by Robert Bruce-Gardner
Copyright 1998 by The Metropolitan Museum of Art, New York. Reprinted by permission
Although the majority of paintings in the exhibition were executed on a cotton support, it is not uncommon to find linen, or, more rarely, silk used. There is little inherent difference between cotton and linen in terms of physical and behavioral properties, and, as yet, the selection of one or the other does not indicate a particular regional practice or association with style. It is the thickness of the thread and the openness of the weave that define the character of the woven support and its functional ability. A thread that is fine but loosely woven will not adequately retain the ground applied to it and so will be prone to flaking and loss when rolled; a thick thread that is too tightly woven will require a proportionately thick ground to cover the weave, but without sufficient key, or interlocking grasp, in the interstices, it will be equally vulnerable.
Most thankas are medium to fine in thickness of thread and density of weave, from fifteen to thirty threads per square centimeter. This was not governed by the dimensions, as the larger paintings were often composed on two or more Strips of cloth that were sewn together; the seams of the joins were sup-pressed by the ground. However, the support of the large Tara appears to be a single piece, suggesting an unusually wide loom of more than thirty-two inches. Small Images can also be found to have composite structures, even an assembly of different weaves, implying either a paucity of suitable material or a veneration for particular pieces of cloth. For instance, a small painting of Tara, measuring only thirteen by sixteen inches, was painted on a piece of cotton that had been holed and repaired before the application of ground and paint; this would seem an unlikely choice of support for the depiction of the god-dess.1 Subsequently, the painting was folded to a fraction of its size, which might indicate that at its consecration it was inserted, among other offerings, into a bronze sculpture. This might affirm the notion that, in addition to the image of Tara, the cloth itself was in some way empowered.
Apart from the celebrated blue-and-white check patterns on the cotton, linen, and silk that support some of the paintings from Kharakhoto, it is rare to find colored threads in early works. However, the threads of the Vaishravana are of dyed red linen, the color of which plays no optical role in the ground or surface image; might this cloth have been the property or even the robe of a revered monk or teacher?
The use of silk-because of its delicate, thin, and finely woven surface-was mostly confined to smaller images; the precisely detailed line drawing and subtle glazemodeling of Ushnishavijaya xecuted on silk with only the thinnest coating of ground; the color of the thread is still visible. Some silk paintings have been laminated onto more robust and durable Supports, seen most notably in the genre depicting the footprints of significant lamas. The reasons for such specificity remain, as yet, unexplained. The preparation of silk would have been somewhat different, but other woven materials were first stitched to thin slats of wood at their edges, which were then tensioned within a larger rigid frame. If required, the tautness could be adjusted at any time during the painting process without exerting particular stress upon single points. The distortion of the weave around the edges is less pronounced when the stitching of attachment to the lath is close and regular, since the tension is then more evenly distributed. Once stretched, the support was probably sized with an animal glue to infuse and seal the fibers. It seems that the size was applied as a fairly dilute solution, as it cannot be discerned in isolation and does not fill the interstices of the weave. A thick layer of size would almost certainly have induced subsequent cracking and delamination, by reducing the key, or tooth, of the fabric and being dimensionally reactive to moisture and becoming more brittle with age.