Customizable Stitch Markers / Clips

I needed a new set of stitch markers and also wanted to learn OpenSCAD, so here's the result. :)

This is a very customizable set of stitch clips. Hit the "Open in Customizer" button to play around with the different options.

### Slicing
Make the initial layer thicker (0.3mm) for better adhesion

### Printing
Make sure the initial layer is good before walking away. It's a quick print anyway.