| 摘要 |
<p>Drawing sheet system comprises a stack of drawing sheets pref. of coloured material, with surfaces which allow easy inscription or painting and partial or complete erasure, pref. of plastic film material. The system may also contain a number of transparent films which can be inscribed or painted on, and a number of electrostatically adhering transparent covering films. It may contain ready printed films which facilitate writing or painting, e.g. for educational purposes. Lead or water-contg, or solvent-contg. paints can be used, without susceptibility to soiling, smudging, or destruction e.g. tearing.</p> |
