_A hushed pattern, a well-kept secret, revealed only by inspiring light from within or from without._
This tealight holder has a 3 mm shell, printable with 2 perimeters, and uses an infill modifier mesh to create a Voronoi pattern sandwiched between the perimeters - thus, you don’t need to worry about overhangs. A semi-opaque white filament reveals the infill pattern when light shines through the tealight holder.
With Cura you can also get a matte effect (and hide seams!) using Fuzzy Skin with a normally glossy white filament.