| 摘要 |
A sheet of paper of similar material has a first seat of concertina folds and a second set of concertina folds which, on folding of the sheet with these folds, lie transversely to the latter. The sheet also has two rigid portions in diagonally opposite corner regions of the sheet, so that the sheet can be unfolded in a single movement, it being possible for the sheet to be gripped and unfolded using only one hand. <IMAGE> |
