I purchased this water bottle while visiting Blenko in October of 2006 and it is etched 2006 on the base. It is also signed by Richard Blenko. Not all of the Yellows are cased but this one is definitely cased in Crystal. Just a reminder in case you missed it in the earlier posts, the Yellows from 2001 through 2012 are all called Yellow. The term sunshine yellow which many of the collectors have heard is a name sometimes used at Blenko for this color but the correct “catalog” designation is simply Yellow. This is the Yellow used to make the Fire and Ice pieces. Yellow when reintroduced in 2000 was called Opaline Yellow but because many of the pieces had no opaline in them, the name was changed to Yellow.