I figured the NFC tags were worth a quick mention, the ones I've used so far have been NTAG2 format round stickers I got from eBay. These cost about £5 for 10 so not free but not overly expensive either. Given these are intended to go on a bottle of resin that costs over £100 and would last for 6-12 months it's not a great overhead.

Below are the tags I got from eBay (sorry about the contrast, they are white on a white strip):

One possible use case of the Reagent Tracker is for refilling of reagent bottles. In a larger lab set-up it is common for solvents and common chemicals to be purchased in bulk and split down to more manageable sized bottles (e.g. a 20L container purchased and split into 500ml bottles as and when needed), or for somebody to make up a bulk lot of reagent (e.g. pH buffer). In this case the NFC tag stays with the bottle but the bottle may end up getting cleaned and re-used.

During my experimentation with the scale I ended up using my tea mug as a test bottle and hence it got NFC taged. I was surprised to find the tag still attached after forgetfully putting it into the disk washer. The coating was removed but the tag stayed with the mug and still worked, even after a second run through the disk washer!

It is also possible to get custom tags, below is an example of one I've previously had made for Tinamous:

Sadly the company that made these are no longer going, however I'm sure there are other places that will do this. It can add an extra level of usefulness to the the tagging, or corporate branding, or an indication that the reagent has been though a certain process (goods in, QA etc.)

It is also possible to get the tags custom programmed, so if for example you regularly have pH 4, 7 and 10 buffers to track, you could have custom tags that include some kind of identifier data to indicate which buffer they were and have a custom colour coded image of 4, 7 or 10 on the sticker to ensure they went on the correct bottle so simplifying the tracking process.