Blastoise F-91W
A clear-resin F-91W with a Blastoise card behind the display
- 2026
- Casio F-91W

The F-91W is the cheapest watch here by a wide margin, which makes it the one worth experimenting on. Nothing on it is precious. If a shell cracks or a backing tears, another one costs less than a strap.
The mod that carries this build is behind the display. The F-91W’s LCD is transparent where no segment is lit, so whatever sits behind it reads as the dial. The stock grey ground comes from a reflective backing stuck to the back of the LCD, and that backing is the only thing in the way.
So I took it off. Behind it went a Blastoise printed on glossy photo paper, with a holographic sticker laid over the print, and the module went back together on top of that. The case itself is untouched.
On the wrist it reads like a normal F-91W. The print is subtle enough that it never competes with the segments, so the time is no harder to read than it was stock.
