| 摘要 |
<p>Transparent notices or diagrams for display via an overhead projector are made using two layers of thin transparent film hot laminated so that the printed message etc. is located on the interface. Pref. the cover sheet and/or the base sheet are mde of polyvinyl acetochloride and feature a smooth surface and a matt surface, the latter being the surface on which the basic information is written or printed, opt. by xerography, before being used as an interfacial surface in the laminate; hot lamination suppresses the optical interference by the matt texture. The individual layers of the laminate may be of differing or similar thickness, typically about 0.15 mm. Print is protected from accidental erasure or from direct interaction with temporary markings made on the external surfaces by e.g. crayons or felt tip pens.</p> |
