These rails can be used to make string art. They can be screwed into a wooden base, and then you loop yarn through the holes to make your artwork. You can print out a little needle as well, to help thread yarn through the holes.

The photo shows a very quick sample string art which I dashed off as a demo, along with some rails and needles. One of the rails in the photo is an early version that cannot be made in the customizable OpenSCAD file I have uploaded, but the changes are minor.

I designed this for use in art and craft projects at an aged care facility and it worked well for that. But I also have ideas to make it better for use in this setting. A new customizable thing entirely will arrive in due course which has a number of advantages over this design. But this one did work.

Due to some oddities in the customizer, the view of a curved rail is tiny, and I don't think you can zoom in.