tympan-
1. A piece of paper used on a press tympan to vary the''. 轮廓纸为调整印刷''。
2. A piece of paper used on a press tympan to vary the press ure that produces light and dark tones. 轮廓纸为调整印刷压力而覆在调压滚筒上的纸，产生明暗相间的色度