It was tighter than a bug screen on a screen door. (I was trying to think of a funny euphemism, but....)
Here’s a link to a similar fabric: 6’x8’ for $22.
http://www.tarpsplus.com/meshtarps-single-tarps-black-mesh-tarps-—shade-screens.html
That’s nice and the price isn’t bad. I was thinking a mesh that tight wouldn’t let air pass through easily. Guess I’m overthinking that. That would catch .22 rimfire which covers the gamut.