I have a Tazlab collar that is made to prevent the dog from getting strangled/caught or avoid another dog getting caught when playing. It has elastic but closes tight when in use as a collar on walks. I don't worry about leaving it on my dog unattended. Its not as "pretty" as some of the leather ones, but the colors are nice and bright. Its more for function anyways. It is well made and has a lot of nice details like a weighed tag area so the tag is always facing down.
I just got some of these: http://www.petexpertise.com/dog-safe...y-stretch.html
safe, lightweight ID band.
I hate to leave collars on un-supervised dogs. The Quillin leather collars go on for walks only. But I've always worried about an un-ID'd dog somehow getting loose or pulling out of the collar. Problem solved.