Spot lamps are small light sources that may create disturbingly high-contrast, sharp shadows. Old LCD monitors have diffuser sheets that can be harvested and cut to shape. The present design is a holder for such diffusers for ceiling-embedded spot lights.

The upper part is printed as a spiral so that it can be printed together with the bottom part. The upper wraps around the lamp and partially goes between the lamp and the ceiling. The lower part snaps to the upper part and holds the diffuser.

Prints the best with a lot of perimeters. 20+ is enough for the default values. PETG printed on a textured PEI sheets works great. You can use the bottom part as a stencil and pencil a circle around it. Then cut it to shape, roughly a bit smaller than the circle (~5 mm smaller with the default values).

The design is fully customizable, but the customizer doesn't work for some reason. You can use OpenSCAD to customize.