...well, sort of. Here are shots of two of the more promising types of pots that spectrasymbol sent, showing the relative translucence.
This shows the yellowish type that I think has the best tactile feel.
This shows it sticky-side-up
This is a wider type with a sort of grid of wires inside, and on ly 2 leads. The surface of this one is kind of like mylar. I tested it for capactiance and resitance. The pad appears to be divided into 4 distinct horizontal areas, giving values of 6, 5, 4, and 3 near the bottom. I'm not sure if you can see but it is sort of split down the middle but both halves give the same readings. On a capacitance setting it looksed like the values were greater in range but it was hard to get steady readings. Maybe I just need a data sheet on this thing.
More Thinking
And thinking
sketches 1
sketches 2
ribbon tests
shebang