OpenTag3D Lookup

Polar Filament has added support for OpenTag3D, an open-source RFID standard for 3D printing.

Look up spool

Enter the serial number of a Polar Filament spool. Example: 50017-FYG5

2 Review / Export Payload Inspect the encoded data or export it for another tool.

Look up a spool to review its OpenTag3D payload.

3 Write to RFID tag Choose a method for programming an NFC tag.

OpenTag3D needs your help! There is no official way to write tags yet. For now, writing a tag requires some technical knowledge and either a compatible app or an RFID writer.

Android WebNFC

Android can write compatible NFC tags directly from a supported web browser.

Web NFC requires a compatible browser such as Chrome on Android.

iPhone: Custom app required

iPhone does not allow websites to program tags through Web NFC. Polar Filament is developing an open-source iPhone app, but it is not live yet.

Some third-party apps can write custom NDEF records, although this feature often requires a paid plan. See the Manual NDEF Record section below.

ProxMark3

This guide only applies to brand-new, blank, unprotected NTAG213, NTAG215, and NTAG216 tags. The Core MFU export is an NTAG213 image and can be written to any of these tags. The Extended MFU export is an NTAG216 image and requires an NTAG216.

Download ProxMark3 MFU (.bin) from Step 2 and place the file in your ProxMark3 client working directory.
Connect the ProxMark3, start its client, place the target tag on the antenna, and identify it: hf mfu info
Restore the MFU dump to the tag's writable user-memory pages: hf mfu restore -f <downloaded-file>.bin
Read the resulting NDEF record to verify the OpenTag3D payload: hf mfu ndefread You can also read the full tag without creating another file: hf mfu dump --ns

Do not add -s, -e, or -r for a normal NTAG. Those options are for special or magic tags and attempt to write UID, version, signature, password, or configuration data. The normal restore command skips the factory UID and protected configuration pages.

See the official Proxmark3 client documentation for hf mfu restore and the MIFARE Ultralight command list.

Proxmark3 Easy image from edvoncken.net.

Flipper Zero (Not yet implemented)

Flipper Zero can write compatible NFC tags, but we do not have a tested guide yet. If you have successfully written OpenTag3D data with one, tell us at discord.polarfilament.com in the #beta-testers channel.

Other NFC writers

Common USB NFC reader/writers are capable of programming these tags, but we do not have a tested guide yet. If you know a reliable workflow, share it at discord.polarfilament.com in the #beta-testers channel.

Sony RC-S370 image by Project Kei via Wikimedia Commons, CC BY-SA 4.0.

Manual NDEF Record

NDEF is a standard container for records stored on NFC tags. It lets compatible readers identify the record type and pass its bytes to the correct application.

Record type: MIME
MIME type: application/opentag3d
Payload: The raw bytes represented by the hexadecimal payload in Step 2, without the displayed whitespace.

4 Read it back Verify the data after writing the tag.

We recommend using the OpenTag3D reader to verify that the contents of the tag are correct. Open the reader and click the Import button to read the tag.

Open the OpenTag3D reader