I don't know if this is still needed, but the dull side is the Teflon
side, (I believe) and the shiny side is the rubber. :)
Shana M.
On Thu, 12 Dec 1996 aldenjc@plu.edu wrote:
> Dear Chem Fans,
> Upon studying for the lab final, I came across something that
> perplexed me. I was wondering which side of the rubber/Tefflon cap is
> rubber, and which is Teflon. As I remember there is a rough dull side and
> a shiny side. I never paid attention to this before, but the lab book has
> mentioned it twice so I thought it might be important.
> Jacob
>
>
>