The tuber of hyacinth bletilla

A light glue obtained from the tuber of hyacinth bletilla is used in ink rubbing to keep a rubbing paper, especially unsized rice paper, firmly attached to a stele.

1. Soak one teaspoon of the tuber of hyacinth bletilla in a quart of cool water overnight.
2. Boil for an hour on low fire. Let it cool.
3. Brush a thin coat of the glue evenly over the surface of an engraving, then spread a sheet of dampened rice paper over the glued area.
4. Tap the paper into all the depressions of the engraving with a large bristle brush while the paper is still wet.
5. Start applying ink while the paper is half dry.