Niño wears a collar we bought at a street fair but you can buy them at dog shows too. It's nylon covered in this waterproof plastic and the guy stamped out a brass name/ id plate right there that he attached. It was only about $15 and has lasted quite a long time. There are several different color and hardware choices too. Let me see if I can find a picture and/or brand or link.
His looks like this, but is aqua blue and of course has the plate.