noun
wet mounting; stretching wet paper or fabric on a board
Refers to the technique of wetting paper or cloth and then attaching it to a flat surface (such as a wooden board) so that it dries taut and smooth. Commonly used in traditional Japanese painting, calligraphy, and crafts.
日本画では、和紙を水張りしてから描き始める。
In Japanese painting, you start by wet-mounting the washi paper before you begin to paint.
水張りの工程で紙が破れないように注意が必要だ。
Care must be taken not to tear the paper during the wet-mounting process.
裏打ち is backing or lining (often for scrolls or calligraphy), while 水張り specifically refers to the initial wet-stretching step on a board.
Compound of 水 (water) and 張り (stretching), from the verb 張る (to stretch). The spelling 水貼り uses 貼る (to stick) instead, reflecting the adhesive aspect.