We have been talking about this but is it really true? Did you know that EVERY piece of float glass has a tin side? This means that if you are working on a single sheet of glass (not a double insulated unit) then you will always be in contact with the tin side whether it is in or outside. Did you also know that most problems usually happen with the tin side? Also that specialty etch companies that do art work on glass prefer the air side? There are reasons for these facts. Now let me ask you exactly what acids react with the tin side and does this happen every time? These are the questions that need to be answered.