warp and fill

Curious…with reference to a roll of glass which is warp and which is fill eg length or width of roll??? and what type of count in either direction provides greatest strength against snapping and depressions.I have heard that flat weaves are stronger lengthways but not as strong as a twist weave for depressions and what about twisted in one direction and flat in the other???

warp is length. glass is the strongest in the direction that has the most strands.