Rocketbook Isometric Grid Paper


Last week I took another look at the various “digital pen” products, and once again couldn’t find one that was worth buying. I like the idea of the Livescribe, etc, but none of them seem to actually work very well, with poor ergonomics, poor performance, poor support, or “all of the above”.

So I took a look at Rocketbook, which is a series of notebooks with custom paper, marked up to be scanned in with an iPhone/Android app and sent to your email account and/or various cloud services. OCR is not handled by Rocketbook, so unless you send it to a cloud service that does that, you get the image only.

If you use any of the upload options, you can’t really rely on confidentiality, of course, but you can always leave the destination checkboxes blank, and uses your phone’s native sharing services to store the scans. (note that the email goes through a third-party service, then to Rocketbook’s server, then to your email provider, rather than just using the phone’s API)

It looked straightforward, and since the app is free and there are sample PDFs available for download, I could try it out before buying. It recognized their markup quickly and reliably, and produced a decent image, so I went ahead and ordered the Everlast notebook, which has a special paper that turns FriXion erasable pens into wet-erase markers. In theory, the Everlast pages can be reused forever, unlike the 5-6 times their heat-erasable product claims.

I’ve had it for a few days now, and after adding a pen loop to keep the supplied FriXion pen handy (3” strip of gaffer tape, with a 1.75” strip stuck across the middle of the sticky side, leaving room at both ends to attach it to the sturdy edge of the cover), I quite like it. I have some color FriXion pens as well, and it captures them nicely.

But of course I want to print my own, and not just the dot-grid they supply. The first hurdle was that the PDF that works just fine on my office color laser printer is unscannable when printed on my home inkjet. Seriously, if I place two printouts side by side, the laser-printed one is recognized instantly, while the inkjet version leaves the app fumbling for several minutes before it figures out that it’s a black box with a QR code in the lower right corner.

I’ve ripped the PDF apart in Illustrator, so I know there’s no hidden magic that’s not reproducing correctly on the inkjet, but somehow it makes a difference. The ink is just as black, the paper is just as white, the resolution is just fine. One thing I did discover is that there are several different versions of the free PDFs, and the one I originally tested with has a relatively narrow black border. The most recent one has a wider border that works better on an inkjet, but someone at the company hacked it together, so it isn’t really an 8.5x11 page, and the destination icons are bitmaps.

My first attempt at a custom Rocketbook PDF is here, and replaces their dot-grid with an isometric grid. This one’s still a bit finicky on the inkjet, but a lot better than their original PDF.

I did it in Perl with PDF::API2::Lite, so I can tweak it until I figure out exactly what their app is looking for. My guess is that the “V” section in the QR code indicates paper type, and the app has a lookup table containing the aspect ratio and relative location of the destination icons, but that by itself can’t explain the difference between inkjet and laser printouts.

11/29 Update

Just tested with the new version of the app, and it’s much more reliable at scanning inkjet prints of both their PDFs and mine.


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