One of my organic experiments. The bottom side is flatten for sitting better on fabric. Prints pretty well from wooden PLA, possibly from some other materials as well. I set the length to 5cm. Finally I resized it to 130% in the slicer for printing.

You may play with the parameters in OpenSCAD to feel the geometry if you like.

Print instructions

Printer brand: Prusa
Printer: i3 MK2S
Rafts: No
Supports: Yes
Resolution: 0.15mm
Infill: 20%
Filament_brand: any
Filament_color: wood
Filament_material: PLA (wooden or bamboo)
Post-Printing: Light sanding can be applied if you use wooden PLA