Simple ribbed lampshade design, fits any standard E27 (40 mm diameter) light cord. I used IKEA HEMMA.
Dimensions: 207x207x210 mm
Print in the vase mode (spiralise outer contour) for a smooth print and material saving. (if your slicer does not support holes in the bottom surface, try using a different slicer - tested in Prusaslicer or Creality slicer)