Oil stains in calligraphy and painting

Absorbent paper! ! ! ! It's expensive, 600 yuan a knife. Liulichang sells them. This is a special paper for painting and calligraphy mounting. Light rail will not absorb the color of the painting itself. We usually iron it several times and rinse it with alkaline water. Of course, we use bone glue to protect the color before processing. I am good at calligraphy and painting mounting.