Paper doesn't need to be told what it's doing. You read it in full sun without a second thought. It doesn't dim, doesn't glare, doesn't ask to be charged. It just holds whatever's written on it, for as long as you need it to.
That's a surprisingly high bar for a screen to clear. E-paper is the only technology that clears it.
So when we started designing M1, a year ago, e-paper wasn't really a choice among options. It was the option — replace the printed chart with a digital one, but keep everything paper already gets right. Visible at a glance in full daylight. Always on. A battery you never have to think about. It's the single decision that makes M1 work.
What we didn't know, going in, was how much there was to learn about it. E-paper refreshes by driving every pixel to black, then to white, before drawing the new image — which is why the screen flashes when it clears itself. It took months of tuning to get that flash fast and consistent, rather than something you notice and wonder about.
The panel itself is small — 320 by 240 pixels — and that's plenty. Clean text, sharp at a glance, enough resolution to carry a proper bitmap image. Paper can't do any of that twice. Print a new chart and the old one's gone; M1 just redraws itself.
For most of that work, there was no glass in front of it. Which meant we found out the way you find out most things in hardware — by watching it happen. E-paper left unprotected against UV degrades fast outdoors. Not over years. Over weeks.
So the glass was never going to be an afterthought. We found a partner who could bond a UV-blocking layer directly onto the panel, and who could offer one of the toughest glasses available in the same process: Corning Gorilla Glass, 0.7mm thick, finished anti-reflective, anti-fingerprint, and matte. The result is a screen that survives hours in direct sun, shrugs off the knocks a working set hands out, and still feels like the paper it replaced — with everything an electronic display can do that paper never could.
The last piece was one we nearly missed. The first batch of glass came back with a masking layer — the black border around the visible screen — so deep and dense that it stood apart from everything around it. Anodised aluminium and e-paper both sit in a slightly grey black. That first masking was a true, flat black. Side by side, the mismatch was obvious the moment you went looking for it.
Most people would never have gone looking for it. We sent it back anyway, for a second run in a custom-matched colour, with the same UV treatment as the rest of the assembly. Now the housing, the glass and the screen sit in the same black, and nothing pulls your eye toward a seam that shouldn't be there.
None of it is the kind of thing you're meant to notice. That's the point. It's the standard the camera world already holds everything else to. We just wanted OBM-1 to belong on the same shelf.