glass buttons

Hi there-- I'm a glass maker [and a newly-minted knitter, hooray!]. I've started to make glass buttons and am wondering if anyone has ideas about where to market them, and more importantly, what're considered the marks of a quality button--short shank, long shank, drilled holes, glued shanks, glass shanks....I really have no idea. I've started working with a spinner/dyer in my area to create matching buttons and yarn for a local shop. I'd like to do this in the best possible way...I treasure the idea that 30 years from now someone will be getting a beautiful "hand-me-down" angora sweater with sparkling glass buttons..... ;) I'm not sure where to go to find info about this, so I thought I'd ask everybody! I know beaders use buttons as closures. What do you folks prefer? Thanks! Cindy