In the 1930s, as an alternative to celluloid, some Japanese companies printed films on paper (kami firumu), often in color and with synchronized 78 rpm record soundtracks. Unfortunately, between the small number produced, varying paper quality, and the destruction of World War II, few of these still survive. To keep more of these from being lost forever, a team at Bucknell University has been working on a digitization project, overcoming several technical challenges in the process.
The biggest challenge was the varying physical layout of the film. These films were printed in short strips, then glued together by hand, creating minor irregularities every few feet; the width of the film varied enough to throw off most film scanners; even the indexing holes were in inconsistent places, sometimes at the top or bottom of the fame, and above or below the frame border. The team’s solution was the Kyōrinrin scanner, named for a Japanese guardian spirit of lost papers. It uses two spools to run the lightly-tensioned film in front of a Blackmagic cinematic camera, taking a video of the continuously-moving film. To avoid damaging the film, the scanner contacts it in as few places as possible.
After taking the video, the team used a program they had written to recognize and extract still images of the individual frames, then aligned the frames and combined them into a watchable film. The team’s presented the digitized films at a number of locations, but if you’d like to see a quick sample, several of them are available on YouTube (one of which is embedded below).
This piece’s tipster pointed out some similarities to another recent article on another form of paper-based image encoding. If you don’t need to work with paper, we’ve also seen ways to scan film more accurately.
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KeyMo Brings A Pencil To The Cyberdeck Fight
Computers and cellphones can do so many things, but sometimes if you want to doodle or take a note, pencil and paper is the superior technology. You could carry a device and a pocket notebook, or you could combine the best of analog and digital with the KeyMo.
[NuMellow] wanted a touchpad in addition to a keyboard for his portable terminal since he felt Raspbian wouldn’t be so awesome on a tiny touchscreen. With a wider device than something like Beepy, and a small 4″ LCD already on hand, he realized he had some space to put something else up top. Et voila, a cyberdeck with a small notebook for handwritten/hand drawn information.
The device lives in a 3D printed case, which made some iterations on the keyboard placement simpler, and [NuMellow] even provided us with actual run time estimates in the write-up, which is something we often are left wondering about in cyberdeck builds. If you’re curious, he got up to 7.5 hours on YouTube videos with the brightness down or 3.5 hours with it at maximum. The exposed screen and top-heaviness of the device are areas he’s pinpointed as the primary cons of the system currently. We hope to see an updated version in the future that addresses these.
If you’d like to check out some other rad cyberdecks, how about a schmancy handheld, one driven by punch cards in a child’s toy, or this one with a handle and a giant scroll wheel?
Sustainable 3D Prints With Decomposable Filaments
What if you could design your 3D print to fall apart on purpose? That’s the curious promise of a new paper from CHI 2025, which brings a serious hacker vibe to the sustainability problem of multi-material 3D printing. Titled Enabling Recycling of Multi-Material 3D Printed Objects through Computational Design and Disassembly by Dissolution, it proposes a technique that lets complex prints disassemble themselves via water-soluble seams. Just a bit of H2O is needed, no drills or pliers.
At its core, this method builds dissolvable interfaces between materials like PLA and TPU using water-soluble PVA. Their algorithm auto-generates jointed seams (think shrink-wrap meets mushroom pegs) that don’t interfere with the part’s function. Once printed, the object behaves like any ordinary 3D creation. But at end-of-life, a water bath breaks it down into clean, separable materials, ready for recycling. That gives 90% material recovery, and over 50% reduction in carbon emissions.
This is the research – call it a very, very well documented hack – we need more of. It’s climate-conscious and machine-savvy. If you’re into computational fabrication or environmental tinkering, it’s worth your time. Hats off to [Wen, Bae, and Rivera] for turning what might otherwise be considered a failure into a feature.
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Homebrew Foil And Oil Caps Change Your Guitar’s Tone
How any string instrument sounds depends on hundreds of factors; even the tiniest details matter. Seemingly inconsequential things like whether the tree that the wood came from grew on the north slope or south slope of a particular valley make a difference, at least to the trained ear. Add electronics into the mix, as with electric guitars, and that’s a whole other level of choices that directly influence the sound.
To experiment with that, [Mark Gutierrez] tried rolling some home-brew capacitors for his electric guitar. The cap in question is part of the guitar’s tone circuit, which along with a potentiometer forms a variable low-pass filter. A rich folklore has developed over the years around these circuits and the best way to implement them, and there are any number of commercially available capacitors with the appropriate mojo you can use, for a price.
[Mark]’s take on the tone cap is made with two narrow strips of regular aluminum foil separated by two wider strips of tissue paper, the kind that finds its way into shirt boxes at Christmas. Each of the foil strips gets wrapped around and crimped to a wire lead before the paper is sandwiched between. The whole thing is rolled up into a loose cylinder and soaked in mineral oil, which serves as a dielectric.
To hold the oily jelly roll together, [Mark] tried both and outer skin of heat-shrink tubing with the ends sealed by hot glue, and a 3D printed cylinder. He also experimented with a wax coating to keep the oily bits contained. The video below shows the build process as well as tests of the homebrew cap against a $28 commercial equivalent. There’s a clear difference in tone compared to switching the cap out of the circuit, as well as an audible difference in tone between the two caps. We’ll leave the discussion of which sounds better to those with more qualified ears; fools rush in, after all.
Whatever you think of the sound, it’s pretty cool that you can make working capacitors so easily. Just remember to mark the outer foil lead, lest you spoil everything.
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Massive Mural From Thermal Receipt Paper
Turning trash into art is something we undoubtedly all admire. [Davis DeWitt] did just that with a massive mural made entirely from discarded receipt paper. [Davis] got lucky while doing some light dumpster diving, where he stumbled upon the box of thermal paper rolls. He saw the potential them and, armed with engineering skills and a rental-friendly approach, set out to create something original.
The journey began with a simple test: how long can a receipt be printed, continuously? With a maximum length of 10.5 feet per print, [Davis] designed an image for the mural using vector files to maintain a high resolution. The scale of the project was a challenge in itself, taking over 13 hours to render a single image at the necessary resolution for a mural of this size. The final piece is 30 foot (9.144 meters) wide and 11 foot (3.3528 meters) tall – a pretty conversational piece in anyone’s room – or shop, in [Davis]’ case.
Once the design was ready, the image was sliced into strips that matched the width of the receipt paper. Printing over 1,000 feet of paper wasn’t without its issues, so [Davis] designed a custom spool system to undo the curling of the receipts. Hanging the mural involved 3D-printed brackets and binder clips, allowing the strips to hang freely with a kinetic effect.
Though the thermal paper will fade over time, the beauty of this project lies in its adaptability—just reprint any faded strips. Want to see how it all came together? Watch the full process here.
Back Up Your Data On Paper With Lots Of QR Codes
QR codes are used just about everywhere now, for checking into venues, ordering food, or just plain old advertising. But what about data storage? It’s hardly efficient, but if you want to store your files in a ridiculous paper format—there’s a way to do that, too!
QR-Backup was developed by [za3k], and is currently available as a command-line Linux tool only. It takes a file or files, and turns them into a “paper backup”—a black-and white PDF file full of QR codes that’s ready to print. That’s legitimately the whole deal—you run the code, generate the PDF, then print the file. That piece of paper is now your backup. Naturally, qr-backup works in reverse, too. You can use a scanner or webcam to recover your files from the printed page.
Currently, it achieves a storage density of 3KB/page, and [za3k] says backups of text in the single-digit megabyte range are “practical.” You can alternatively print smaller, denser codes for up to 130 KB/page.
Is it something you’ll ever likely need? No. Is it super neat and kind of funny? Yes, very much so.
We’ve seen some other neat uses for QR codes before, too—like this printer that turns digital menus into paper ones. If you’ve got your own nifty uses for these attractive squares, let us know!
3D Printing A Bottle Labeling Assembly Line
We’re not completely sure why [Fraens] needs to label so many glass bottles at home. Perhaps he’s brewing his own beer, or making jams. Whatever the reason is, it was justification enough to build an absolutely incredible labeling machine that you could mistake for a piece of industrial gear…if it wasn’t for the fact that majority of the device is constructed out of orange 3D printed plastic.
As we’ve come to expect, [Fraens] has documented the build with a detailed write-up on his site — but in this case, you’ve really got to watch the video below to truly appreciate how intricate the operation of this machine is. Watching it reminded us of an episode of How It’s Made, with the added bonus that you not only get to see how the machine functions, but how it was built in the first place.
Nearly every part of the machine, outside the fasteners, smooth rods, a couple of acrylic panels, and a few sections of aluminum extrusion, were 3D printed. You might think this would result in a wobbly machine with sloppy tolerances, but [Fraens] is truly a master of knowing when and where you can get away with using printed parts. So for example, while the glue rollers could be done in printed plastic, they still needed metal rods run through the middle for strength and proper bearings to rotate on.
Looking at the totality of this build, it’s hard to imagine how it could have been accomplished via traditional methods. Sure you could have sourced the rollers and gears from a supplier to save some plastic (at an added expense, no doubt), but there’s so many unique components that simply needed to be fabricated. For example, all the guides that keep the label heading in the right direction through the mechanism, or the interchangeable collars which let you select the pattern of glue which is to be applied. Maybe if you had a whole machine shop at your disposal, but that’s a lot more expensive and complex a proposition than the pair of desktop 3D printers [Fraens] used to crank out this masterpiece.
If the name (and penchant for orange plastic) seems familiar, it’s because we’ve featured several builds from [Fraens] in the past. This one may be the most technically impressive so far, but that doesn’t diminish the brilliance of his vibratory rock tumbler or cigarette stuffing machine.
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