| 摘要 |
<p>The layer of capsules which contain pref. colourless chromic based ink is provided on an opaque or semi-transparent plastic film, and is pref. covered with a plastic film having a coating of ink activator which renders the ink visible. the opaque or semi-transparent film may be polyethylene, polypropylene, polyvinyl, chloride, polystyrene, polyester, polyamide, polycarbonate, cellulose acetate, cellulose nitrate, and may have a matt, foamed, or pigmented surface. The copying paper is water proof.</p> |
