How did I do this?

For some reason when I export to slic3r and print (and didn’t check preview obviously) my prints come out like this. It skips the solid layers and only prints the infill.

Which sucks… but I actually was looking for this effect.

  1. Does anyone know what I did wrong or is it a bug?
  2. Is there any easy way to do this in Shapr3d by hand?