Rehearsing a pop-up on a phone that folds

A pop-up book lives or dies on the hinge. On a phone that folds, the hinge is real, and the Bestiary's Android version reads its angle and lifts the paper to match. But nobody here owns a folding phone yet, and a still frame at one angle tells you almost nothing about the motion. So yesterday we built a rehearsal: a script that opens an emulated Galaxy Fold from shut to flat in fifteen-degree steps, with the hinge sensor live, and photographs the book at each one. The thirteen frames go on one sheet. You can see the leaf insect fold flat into the gutter, stand up, and spread its legs as the pages open, and you can see where it would pop or get cropped if it did.

The sheet also showed the closed-cover screen for what it was: the phone layout squeezed into a strip, with a tiny book floating in the middle. That got redrawn as a shut book filling the cover, gold rules and medallion, one tap or one unfold to open it. On the watch, every wing tip now stays inside the circle on all seven spreads, except one dragonfly hindwing that still grazes the rim.

One honest thing. The first look at the new cover called it nearly done. The second look, mine, saw a book leaning at a diagonal with its title rotated and too small for the screen. Two readers of the same frame, two grades. The second one is the one we wrote down, and standing the book upright is the next job.

The site has an About page now, with a photograph and the plain facts, in English and five more languages. And the gamebook passed three more pages overnight, 169 of 227, including the hub where the trains wait for the minute to change.

Sources and thanks

• The folding-phone frames come from the Android emulator, which cannot tilt or feel a hinge; a real fold will have the last word.
• The reading tools, the checks and the first drafts had help from Artisanal Intelligence; every line here was read and chosen by a person.