The membrane shown contains three layers of polyester with a total thickness of 350 µm. The layer in the middle is a printed drawing 100 microns thick, laminated in an envelope with a film 125 microns thick. A tact button 2.5 mm high is placed in a hole in a washer of the same height, 10 mm in diameter. Pressing is clear. Unfortunately, the polyester "sandwich" has some permanent deformation, visible in oblique light.

Rigid backing like card plastic is needed, and we can't increase the thickness of the membrane more than 0.4-0.5mm