| 摘要 |
A parallel straightedge which may be attached to any drawing table wherein the straightedge is arranged for adjustment and is provided with a braking arrangement to allow the straightedge to be fixedly held in any given position and/or orientation. The bottom of the straightedge is arranged on a pair of rollers outboard the working area in order not to smudge the drawing contained thereon. A removable plastic insert along the edge of the metal straightedge bar provides a consistent transparent ruling edge for drawing straight lines while providing a nick-free edge as a guide for cutting instruments when the transparent edge is removed.
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