Glass can have a grain in it from the manufacturing process although I
doubt most people would ever notice it. You do take this into
consideration in stained glass work but that is usually a different
type of glass.


I grind and polish telescope mirrors and in the process have learned a
fair bit about glass. To the best of my knowledge, properly annealed
and polished plate glass has no grain or direction. In fact the
purpose of the annealing process is to remove strain (there's usually
some residual strain but it's trivial).

My wife did some stained glass work and Perry is correct, some stained
glass is made with ripples or ridges or surface texture. When cutting
that kind of glass one must consider the direction of the surface
texture. But for ordinary plate glass it doesn't matter which edge of
the big sheet you cut the strip from....

Best -- Terry