A ruler with wheeled cornices.

A ruler with a certain interest.

Size tick marks: 1, 5, 10mm scribe lines have different lengths, increasing discrimination and efficient reading.
Angle line: angle measurement and line drawing in the range of 10 to 90.
Vertical tick marks: Draw parallel lines.

The ruler is 2mm overhead, making the ruler into a seesaw shape. While moving flexibly back and forth, the ruler can cross the unfinished line of the new painting to reduce the pollution of the paper.

The initial version of the serious-the cornice ruler
Cornice: It's easy to pick it up. It's good to see whether it's positive or negative.