The largest action in the history of Prusament is here. We’re upgrading the Prusament spool! The new spool comes with a familiar yet different design and several cool features you’ll love. This includes improved thermal resistance when drying, easier refills, and slimmer dimensions. But the biggest feature is one you can’t see at first glance: a fully reusable and open-source NFC Tag.

With the OpenPrintTag NFC, we are setting the standard for all smart spools – It’s designed to work across brands and ecosystems. It is free to use, free to extend, and open for anyone to build upon. There’s a lot to talk about, so let’s have a look at it, shall we?

In case you didn’t know, NFC (near-field communication) is a method of wireless communication between digital devices over a distance of several centimeters. This technology is commonly used in contactless payment systems, keycards, etc.

Why we need smart spools

Over the last decade, 3D printers have evolved from complex hobbyist kits into user-friendly tools. But as printers have gotten smarter, one core part of the process has remained stubbornly manual: the filament interaction. To truly streamline the entire workflow, we need smart spools.

The most immediate benefit is automatic material and color recognition. This simple step eliminates tedious menu clicking and a source of user error. It’s incredibly easy to grab a spool of black PETG, thinking it’s PLA, a simple mistake that can ruin a print. A smart spool removes that risk entirely. The printer simply knows what material is loaded, so the user can’t select the wrong profile by mistake.

Beyond that, smart spools solve the problem of tracking remaining filament. No more guesswork, no more weighing spools, and no more paused unfinished prints in the morning because the filament ran out.

The possibilities expand even further for print farms and professional use. Imagine having digital material libraries, real-time inventory management, and full traceability for every print, knowing exactly which model was printed with which specific spool. This is the level of automation and reliability that smart spools unlock.

The reality of today’s “smart” spools

The vast majority of spools on the market cannot communicate with the printer at all. There are a few solutions for smart spools on the market. Some are inspiring, some are locked down, and most are still only proposals. But until now, none have been brought to market by a manufacturer with the reach to actually set a de facto standard. And we did thorough research on whether there is an already existing system that would work universally throughout the whole 3D-printing community. But as we did, we stumbled upon several problems among all the solutions.

Most of them are brand-specific and proprietary. Everyone is using their own language, and while some are close to our idea, others even prevent the user from rewriting the data and using the full potential of smart spools. This is something we know from 2D printing – every ink cartridge (or toner) is brand and product-specific. You have to buy specifically the one product tailored for your printer. And everyone hates it.

Source: imgflip.com

The 3D printing community, on the other hand, showed that everyone can benefit from using one standard for everything. After all, how would you like to use 1.75 mm filament for one brand, 2mm for the second, 1mm for the third, etc.? Obviously, this wouldn’t work. But no matter how funny this sounds, the smart spools of today are very close to it. Why can’t there be one standard for everything?

Another problem is cloud dependency. Many smart tags are just a little bit more than an ID, which forces you to rely on the manufacturer’s database or cloud service just to identify a filament. Without an internet connection, the tag becomes simply a useless piece of tech.

And finally, some manufacturers use encrypted, digitally signed RFID tags, which only they can create. In extreme cases, the printer might be set to work with the signed RFID tags only. This forces the user to buy only the manufacturer’s products, no matter the costs. We believe that this approach shouldn’t have its place in the world of 3D printing.

All of these examples tell us about the sad reality of various approaches scattered among the brands. There are many standards, and we think it’s time to unify them.

OpenPrintTag: The NFC standard for all smart spools

We are proud to present a complete, open standard designed to fix everything wrong with the current landscape. We built OpenPrintTag from the ground up to be the definitive solution for the entire industry, based on a foundation of openness, offline functionality, and reusability.

Works Offline by Design

The single biggest difference is that the tag is writable. It’s not just a tag that holds an ID; you can write important data directly to it. All essential data – material, color, key print settings, and remaining filament – is stored on the tag. Your printer doesn’t need Wi-Fi or a cloud service to identify the spool.

Fully Open-Source

OpenPrintTag is a published standard that is completely free to use, free to extend, and works across brands. Anyone can build on it without any licensing fees. This is critical for making it the one standard that everyone can adopt. All specifications are available at specs.openprinttag.org.

Reusable and Rewritable

This is what a smart spool was always meant to be. Your printer or a mobile app can write the exact remaining filament length back to the tag after every print. No more guesswork. When a spool is empty, peel the tag off, stick it on any filament you own, and flash it with your phone. Instantly, your old spool is smart. No vendor lock-in, no waste.

Smarter Hardware & Readability

The hardware itself is clever. The tag is a large circle, which means it can be read and written to in any orientation. You don’t have to wait for the spool to spin to a specific position. It’s powerful enough to be read through an entire 2kg spool, so one tag is all you need – no more complex systems with a tag on each side. The data is always in sync.

Instant Info on Your Phone

The tag also contains a link to an online resource. Anyone can scan it with a standard smartphone and be taken to a rich webpage with detailed product information, safety datasheets, and even advanced data like filament diameter consistency graphs. It turns a simple spool into an interactive product guide.

More Than Just Filaments

The OpenPrintTag standard is designed for the whole industry, including other materials like resins for MSLA printing. It’s a universal standard where previous attempts were designed for filaments only.

Adopting the New Standard

How do we get this standard to gain traction? Adopting a new standard like this faces a classic chicken-and-egg problem: It makes no sense to add readers to printers if there are no universal smart spools. And it makes no sense for manufacturers to make smart spools if no printers can read them.

To solve this, a major manufacturer has to lead the way. We are taking that first big step.

Starting today, every new Prusament spool we manufacture includes OpenPrintTag.

But it’s not just us. We want this to be a universal solution, and we are already in discussion with several other major brands who are testing or have shown interest in OpenPrintTag. Over time, you will see it being used by more and more companies.

From now on, we also offer packs of blank OpenPrintTags on our e-shop to use with all your other filaments. One pack contains 10 OpenPrintTags and costs 5.99 USD / 5.99 EUR (VAT incl.). With this, we encourage all makers to develop their own smart spool solutions. And we mean it: Even if you work with another printer, feel free to ask us about the OpenPrintTag and we will gladly help you.

Our strategy for now is to phase out the old spools first – using nice discounts in our Black Friday deal. In the meantime, we will update all of our Prusaments with new spools equipped with the OpenPrintTag, making sure there are millions of OpenPrintTags in circulation. Once the spools are in the ecosystem, rolling out plug-and-play readers for our printers becomes the logical next step. Our universal solution compatible with most Prusa 3D printers will be ready starting in Q1 2026. Meanwhile, our PRUSA.app team will be continually adding new features for you to try. First, you can use your mobile app to read the tag starting next Monday, and the possibility to write will follow on 18th November.

A New Spool for a New Standard

Compact design with a locking mechanism

Adding the OpenPrintTag to our spools required some structural changes. We took this opportunity to update the spool in several ways. So, while we stayed loyal to our signature hexagonal grid on the spool faces, everything else changed – even the box, which can now be recognized by its dark color and light graphics.

The new spool is now 3 mm slimmer and with some extra holes in it. With its slimmer dimensions, the spool ensures compatibility with a wide range of multi-color and multi-material printing systems. And the extra holes? Those are simply a part of the locking mechanism of the spool sides.

Let’s be honest, the old system was not perfect. The paper core had several flaws. Especially when drying at higher temperatures, the material slightly relaxed, and in some scenarios, the spool fell into pieces. The obvious solutions to this issue were gluing the spool or using bolts and nuts to secure the spool faces in position. It worked, but it was far from ideal. Our new solution is simple: We replaced the original paper core with a plastic one equipped with a locking mechanism, and we manufacture the whole spools from recycled polycarbonate. This ensures high reliability at temperatures up to 100 °C. And the High-Temp spools we use for PEI resist up to 150 °C, even with the OpenPrintTag inside.

Prusament spool refill. Note that the spool uses a strong locking mechanism to prevent accidental release. You can download a special tool for simple and easy unlocking.

Another huge advantage of the locking mechanism is refilling the spools. This has never been easier, and changing the filament can now be done in a matter of seconds. Simply unlock, refill, and lock. And since we changed the core from paper to plastic, we also made a small adjustment to the Prusament refill. We started manufacturing the spools without the paper core, as it’s no longer needed. Also, we changed the refill weight from 1000 to 900 grams for a comfortable fit on the spool. The 1000g refill would be too close to the spool edge and might cause printing errors. This also means that we lowered the price proportionally: One 900g spool will cost you 27.49 USD / 23.49 EUR (VAT incl.). You can get the refill spools at our e-shop later this November.

Note that old refills don’t fit the new spools as they’re wound on a paper core. The new refill fits on the old paper core; however, due to the change in spool dimensions, there is a larger clearance, which increases the risk of errors. We recommend using a new refill with new spools only.

Our plans for the future

That was a lot of information, wasn’t it? But totally worth it, as we want you to fully understand the huge potential we’re working with. It is worth mentioning that we don’t stop here just by throwing the OpenPrintTag at you. We will continue to gradually build the whole ecosystem and support around it, just as we do with PrusaSlicer. As we already said, we work on a universal solution for most of our 3D printers to be OpenPrintTag-ready (Q1 2026), and we will provide you with ways to read (next Monday) and write the tags through the PRUSA.app (18th November). Also, we hope that more and more brands will pledge to join our initiative. In the meantime, feel free to study the specifications and play with it. We’re looking forward to your new and amazing creations!

Happy printing!