摘要 |
<p>The underlay is composed of two sheets of card, one laid on the other. The upper sheet (100) has the cut-ins for the closed-cut main edges (11,21,31) and the lower sheet has the cut-ins for the corresponding closed auxiliary edges (12,22,32). The two sheets are positioned so that they can be joined to each other, e.g. by the application of glue or adhesive foil. The top side and bottom side of the sheets forming the underlay may differ in thickness, material properties and surfacing.</p> |