straight-edge

A heavy blade between sword and dagger, with curved back and straight edge, fitted for almost any use.

The slanting or the straight-edge form may be used, to agree with the indented or the block style of paragraphing respectively.

Now slowly move the level along the straight-edge, and the bubble should remain exactly in the centre.

Get the adjustable-pin stretcher for scallop curtains, and stationary stretcher for straight edge curtains.

Most blades display one excurvate and one recurvate or, rarely, straight edge.