norfolkfox was asking on Ukfur if anywhere did diamond shaped tags.
None of the places i buy from do them so i suggested some of whats called 2-ply plastic.
This is a thick base colour layer with a thin layer on top. you engrave through and it exposes the base.

Normally used for signs they work well for other things. Like these collar tags

This is the final Brass on Black tag. And it really does not photo well. but imagine a really shiny brass. I was amazed when i got the large sheets of it. the small sample in my binder really doesn't do it justice o.o