My boys often go naked too while indoors. They run around like they are gleefully streaking me when they are sans collars. But I will buy any width usually for my boys, although I find I prefer the 1.5" ones the best.

Diane did a great job of summing up the need behind the martingale collars. I am thankful there are so many great collar designers out there, dedicated to making some beautiful martingale collars -- non-greyhound-owners should check out some of the sites since the collars will work on your pooches too. If you want the recommendation of some great sites, PM me (I don't know how much free advertising I'm allowed to do here!)