Page 50 - Tibetan Thangka Painting Methodsand Mat, Jackson

To mark the first diagonal line on the canvas using pieces connected by a hinge, with one leg sharply
this type of marking string, Legdrup Gyatsho first placed pointed and the other having some provision for holding
the stick end of the string in one corner of the prepared a charcoal crayon. The second common type of compass
cloth. With his right hand he held the stick with its described by our informants was the "board compass"
notched end down, positioning the end of the string (skor pang). This was used by artists from many parts
(and the end of the stick) in the exact corner. Next, with of Tibet for drawing large circles. The board compass
his left hand he stretched the string across the cloth was made from two pieces of wood: one long slat and a
to the diagonally opposed corner, and held it there by smaller, pointed block. The pointed piece had a hole in
pressing down on it with his thumb. Then - still it through which the slat was passed. The point on the
holding the end of the stick in place, by clasping the small block determined the center of the circle or arc,
shaft in the palm of his right hand - he carefully while the drawing was done with a charcoal pencil fixed
lowered the top end of the stick until he could reach in the end of the long thin slat. The charcoal was
and pluck the string with the index finger of the same stationary; different radii were achieved by moving the
hand. The resulting snap of the string against the canvas small pointed block up and down the stick. Once in
released an imprint of coloured powder in a line along place, the block was secured by inserting a thin wooden
the entire length of the taut string. The artist marked the wedge into the hole between the block and the long slat.
second diagonal in the same way, and in so doing he
established the central point of the painting area, the
intersection of the two lines.

Wangdrak using a marking line.

Vertical and Horizontal Axes

Next the artist determined the vertical and horizontal Two forms of compass.
axes. As above, he used a marking line, but he could also
use a compass (skor thig). Two main types of compass To establish the vertical axis (tshangs thig), the
were used in Tibetan art. The first, which was used for artist began by determining four points on the diagonal
drawing small circles, was similar to the simple metal lines that were equidistant from the intersection of the
compass common in the West: two wooden or metal lines. This was done with either a ruler or compass.

46 SKETCHING AND THE THEORY OF ICONOMETRY