Putting a puzzle PDF on a reMarkable.

The cable route needs no account and no network. On the tablet, open Settings, then General settings, then Storage, and turn on the USB web interface. Plug the tablet into a computer, open 10.11.99.1 in a browser, and drag the PDF into the window. The tablet's own library appears in that page, so you can also pull files back off it the same way.

The USB web interface toggle only appears when the cable is one the tablet will talk over, and reMarkable 2 owners report that even the supplied cable sometimes works in one orientation and not the other. If the toggle is greyed out, turn the plug around before looking for a fault anywhere else.

The desktop app for Windows and macOS and the mobile apps do the same job over the reMarkable cloud. Drop the PDF in and it syncs to every device on the account. Either way the file is stored as a PDF, not converted into something else, so the pages arrive as they were drawn.

USB transfers take PDF, EPUB and rmdoc files, up to 100 MB each. A puzzle book is a few megabytes of vector, so nothing here comes close to that ceiling.

The reMarkable 2 draws 1404 by 1872 pixels at 226 ppi, which is a usable page of 6.21 by 8.28 inches. The Paper Pro is bigger and slightly denser: 1620 by 2160 pixels at 229 ppi, or 7.07 by 9.43 inches. Those are two different pages, and a reader can only reach one from the other by shrinking it.

So the reMarkable 2 edition is drawn at 447 by 596 points and the Paper Pro edition at 509 by 679 points, each matching its own screen to within a rounding error. The reader has nothing left to scale, and a grid drawn at the size it will be read keeps its line weight and its clue digits.

Open the wrong one and the tablet does what any reader does with a page that does not fit: it shrinks the whole thing, clue numbers included, and leaves you pinching in to read a column you were halfway through. It costs nothing to keep the right file, so use the one named for your device.

Shade a square with a short stroke and mark a square you have proved empty with a light cross. The crosses are worth the extra motion: on a 20 by 20 grid they are what stops you working out the same square a second time.

The eraser matters more here than in a notebook. Hard nonograms are solved by assuming a placement and following it until something breaks, and that only works if backing the assumption out is quick. Erase the branch, keep the crosses you proved before it, and carry on.

The pages are pure black-and-white vector with no grey fills, so there is nothing for the screen to dither and little for a refresh to leave behind. The tablet editions are hyperlinked as well: the index takes you to a puzzle, Answer takes you to its solution, and Back returns you to the grid.