A: Float glass has a tin coating on one side that will affect silver stain and some enamel colors. You should always test float glass with a short wave ultraviolet light (sometimes marketed as a Tinscope or Tin-light). Mark the appropriate side of the glass for your use. Silver stain takes more intensely on the tin side of float glass. Enamels are another story. Sometimes interaction with the tin side is bad. I have had problems with some blue, green & turquoise enamels going grey or black. Other enamels, especially gold based colors – like pink, magenta, red & violet actually are more intense and saturated on the tin side - go figure! The answer, if you haven’t guessed it, is to test each color first.
Here is the link to the page on this blog that references UV light & Float Glass: http://thepaintedwindow.blogspot.com/search/label/UV%20light
As far as texture goes, that’s a subjective call. Personally, I paint on mouth-blown Lambert's or Desag (which is similar to Artique). I prefer the texture of these glasses. If I’m painting a face I would avoid a mouth blown glass with a lot of seeds and choose something smoother but surface striations are OK by me – that’s what we’re paying the extra money for after all! If you really find the Artique texture objectionable you can always flip it over – the back side is considerably smoother.Happy painting!