Hi!
I am a total newbie and trying my hardest to learn and research before asking questions, but I’m at a loss. Is it safe to engrave on TPU (Thermoplastic Polyurethane)? We raise cattle and are wanting to customize some tags, but I can’t tell if it’s safe or not based on all my research.
Any help would be much appreciated!!
All of the cattle ear tags I’ve tried just melted or caught fire.
Well, darn. Thank you! I definitely am not looking to start a fire 
We use the ear tags on our kennel gates to let anyone know which dog is in that run at a glance. I’m not aware of any soft flexible plastic that will engrave, but many people engrave silicone watch bands. If you could find a small amount of that material to play with, you may be able to cut and engrave totally custom ear tags.
Have you though about anodized aluminum? I’m not sure how well it would hold up, but they also make a two-ply acrylic with contrasting colors.
Re:flexible plastic…check out the Duets plastic on BF Plastics. I made ear savers from them; I didn’t engrave but I believe it is meant to be. It’s pretty flexible too.
I didn’t think about silicone, but that would probably work. I’m wondering if Richie tags would work, it looks like they sell them as “engraveable” - I’ve reached out to see what they’re made of and if they truly would work this way. I’ve engraved on two Apple Watch bands now and it was simple enough…now to find some material!
I hadn’t considered either of those. For keychains and other more decorative uses I bet the two-ply acrylic would work for part of what I need it to do!
Thanks for the suggestion! I just requested a sample from them.
Please let me know what you find, especially something similar to the watch bands.
Someone had posted here about using “plastic” file-folders. I don’t remember what they determined the material to actually be. Not much use, I know…
If the tags are all the same you might find that a mold made of walnut or maple that can be filled with one of the hot glue materials might work well. Obviously some oil or wax i n the mold to keep it from sticking would be needed and even a nylon ribbon across would make it quite strong.
Did you try the Ritchie tags? This has been something that I’m looking into but haven’t found anything yet