Buying guide
NFC tags for filament spools
Some spools come with a tag from the factory. For everything else, a sticker tag costs pennies and makes any spool scannable.
Tags that come on spools
Several filament brands ship their own tags, and my readers decode them as they are:
| Brand / format | Tag chip | Notes |
|---|---|---|
| Bambu Lab | MIFARE Classic 1K | Works out of the box. |
| Creality (CFS) | MIFARE Classic 1K | Encrypted tags included. |
| Snapmaker (U1) | MIFARE Classic 1K | Uses the published key derivation. |
| Qidi | MIFARE Classic 1K | |
| Anycubic (ACE), Elegoo | NTAG21x | |
| OpenPrintTag (Prusa) | ICODE SLIX2 (ISO 15693) | Needs a PN5180 or ACR1552U. Includes remaining weight. |
Tagging your own spools
For spools without a tag, stick on an NTAG216 and write one of the open formats to it with a phone app or the format's own tool:
- OpenSpool: a small JSON record with material, colour, brand and temperatures. Simple and widely supported.
- OpenTag3D: a more detailed open format.
- TigerTag: compact, with an offline product database.
- A Spoolman link: if you run Spoolman, write the spool's URL (or
web+spoolman:s-<id>) and the reader pulls everything from Spoolman.
You don't even need to write anything. With Spoolman, zmod_nfc can match a spool by the tag's unique ID alone.
Why NTAG216?
- 888 bytes of memory. NTAG213 has 144 and NTAG215 has 504. An OpenSpool record fits in any of them, but the 216 leaves room for longer formats and URLs.
- Every reader reads it. PN532, RC522, PN5180 and PC/SC readers all handle NTAG, and so does any NFC phone.
- Rewritable. Re-tag a refilled or reused spool.
Where to stick it: on the spool's side wall near the hub, where it ends up close to the reader when you hold the spool to it. Avoid putting it directly on metal, which detunes the antenna.
Reading them
Any of these readers works with NTAG216. See PN532 vs RC522 vs PN5180 to pick one, then build the Wi-Fi reader or the USB reader for Zmod.