I upgraded to the new Prusa MK3 R3 extruder design and needed to do some quick fine tuning of the Z axis for most of my filaments. Didn't want to waste time and materials on 20mm calibration cubes (love those cubes btw) so I made some filament swatch with labels to calibrate that could also be clipped onto the Prusa MK3 frame to keep track of your filament inventory. There's also a hole to attach the swatches to some kind of loop if you want.

Each type of filament swatch has a different height (not including the clip legs, which are 5mm tall) to tell the filaments apart at a glance when clipped to the printer's frame. All swatches are 2mm thick.

PP (18mm) PLA (20mm) PETG (22mm) ABS (24mm) HIPS (26mm) FLEX (28mm)

Dimension drawing (2:1 scale) included if you want to check your calibration. Just remember the height (not including the bottom clip part) varies.