A method was found to conserve paintings on canvas by substantially reducing hygroscopicity without changing color, texture, vapor penetration and physicomechanical characteristics. As a result of this treatment the canvas hygroscopicity is reduced so much that, in the course of restoration, there is no penetration observed to the reverse side of the painting by restoration (sturgeon) glue aqueous solutions. This makes it possible to eliminate the stage of lining the painting on a new canvas and carrying out restoration by using lesser quantities of restoration adhesive. This new technique leaves the reverse side of the painting uncovered, which is very often valuable as the available signatures, inscriptions, and dates remain visible. Another important aspect is the better preservation in conditions of variable temperature and humidity occurring in museum exhibition and storage.