I am looking at the magna fabrics for ripstop, and they have this 40x34 ripstop nylon. 1.35 ounces/sq yard. Anyone know what the 40x34 denier means? I have a couple guesses, but my google-fu is failing me.
1) Different thread thicknesses going vertically vs horizontally.
2) 40D for the calendaring threads, 34D for the rest.