A flat 20 cm desk ruler with a 0–20 cm scale. All the marks are raised and print in a second colour — longer ticks at each centimetre, shorter ticks every 5 mm, and raised numbers from 0 to 20 with the zero and 20 set slightly in from the end. Shown in white and blue, but any two colours work.

Printing

• One piece — no supports, no assembly
• The second colour is just a single filament swap mid-print
• Works fine in a single colour too

Printing in one colour? Go for a matte tone with a bit of depth so the details catch the shadows — grey, dark blue, black, forest green, or burgundy all make the numbers and ticks pop.