Open source, DIY-friendly, supported here
OpenSpool came out of the community wanting an open way to tag spools without a vendor's blessing. SimplyPrint supports it natively, so the cheap NTAG stickers you already have can carry a full spool identity - read and written from the same inventory as every other standard.
What OpenSpool is
OpenSpool is a community DIY open standard that stores filament data as NDEF records on ordinary NTAG tags. It's open source and intentionally simple, so anyone can tag a spool with cheap, widely available stickers - no proprietary hardware, no vendor sign-off. SimplyPrint reads and writes it like any other standard.
How to use OpenSpool with SimplyPrint
Three steps from a cheap sticker to a fully tracked spool.
Create an OpenSpool tag for any spool
OpenSpool is open source and vendor-neutral, so you can tag any spool you own with a cheap NTAG sticker and have it recognized by any OpenSpool-aware tool. Write it once in SimplyPrint and the spool carries its own identity wherever it goes.
Open, not locked to one tool
Because OpenSpool uses plain NDEF records on ordinary NTAG tags, a tag you write in SimplyPrint isn't locked to a single tool - any reader or software that supports the OpenSpool specification can read it. Write once, read it wherever OpenSpool is supported.
Open source by design
OpenSpool is open source and community-maintained, which means the format is public and anyone can build on it. SimplyPrint supporting it natively means you get the convenience of NFC without committing to any one company's ecosystem - the spool's data belongs to you.
Write on phone or desktop, tracked automatically
OpenSpool's NDEF-on-NTAG format reads and writes from your phone or the desktop NFC Agent. Once a spool is identified, usage is deducted automatically from the G-code of every print you start - so a DIY tag gives you the same accurate remaining-weight tracking as any branded spool.
How automatic tracking works
Written and ready
A clear confirmation once the tag is encoded
When SimplyPrint finishes writing a tag, you get a plain confirmation that the spool's data is now on it. From that point the NTAG sticker carries the spool's identity, so any compatible reader can pull it up and usage keeps deducting as you print.
OpenSpool is not OpenPrintTag
The names are similar but the standards are not the same. OpenSpool is a community DIY standard using NDEF on NTAG tags; OpenPrintTag is Prusa's standard built on NDEF and ICODE SLIX. SimplyPrint supports both, so you can use whichever fits - but a tag written for one isn't a tag for the other.
OpenPrintTag supportPlan access: what's included?
Reading OpenSpool and the filament manager are on every plan. Writing tags uses your monthly NFC-write allowance.
| Feature / Limit | Free | Basic | Pro | Print Farm | Enterprise | School | Cloud Slicer | Filament Manager |
|---|---|---|---|---|---|---|---|---|
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Filament manager
Spool records and automatic usage deduction, on every plan including Free.
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NFC tag writes per month
How many NFC tags you can write to spools each month.
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10 | 30 | 100 | 10 |
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