Photographic precision encoder strips
a photographic mylar film image of precision encoder lines. The overall length of the strip is about 15.5". The actual encoder image is about 13.5"L.
I know there was a thread somewhere about DIY optical faders …
Ah yes - looks like and HP inkjet horizontal positioner strip.
The higher end old ones have a precision slotted metal strip instead. Time to head down to the scrapyard!
I’ve done binary linear ones by printing them on acetate with a laser printer. I did a circular cyclic grey code one once too, for a sort of digital compass, (then I discovered fluxgates).
Mike