The mesh is made from a thin, yet stiff thread material with a camo pattern etched into it. You can see through it but from the outside it's really hard to see you unless you've got all the windows open and are "skylighted" from the light coming in from behind you.
The mesh is made so that a broadhead will pass through it without effecting the arrow flight. When you shoot through it, it leaves a small hole exactly the dimensions of your broadhead which you can repair with some really fine thread, or after shooting through it several times, you can just order replacement windows, or do what I did and switch the window out with one you havn't shot through yet. Lets face it, how many shots are you gonna put through it in a season?
The one kicker with the shoot through mesh is that the broadhead MUST be a cut on contact type with razor sharp blades.
Broadheads with any kind of blunted tip, or a tip that has been damaged by practice do not work well and will cause the arrow to fly erratically. I switched to a two blade Stinger last year just for this reason.
The best thing to do is simply test it on your hunting heads and then switch the windows out or turn your blind so that a fresh window is facing in the direction your gonna shoot.
Beleive me, when your sitting in the blind and a deer is standing within touching distance, you'll see how well these things work!!