| 摘要 |
<p>A letter blank has leading and trailing edges (1 and 2) and side edges (3 and 4). The blank includes a central oblong rectangular letter portion (108) and marginal edge portions in the form of gummed marginal flaps (7, 8 and 9). The letter portion (108) can be folded into three equal portions by folding along two crease lines (5 and 6) to form its own envelope which can be secured by means of the flaps. The blank meets specified criteria which enables it to be printed by an offset litho process, and further blanks are described which can be similarly printed.</p> |
