securing the press Wall Paintings at Mogao Grottoes
 

Securing the press after grouting. After grouting, absorbent materials are applied to the surface of the painting and held in place with a press. The absorbent layers absorb salts mobilized by the water in the grout. The painting is monitored and the presses changed regularly over the course of the drying of the grout. Not until the grout has completely dried are the presses removed. Photo: Francesca Piqué