Just received a backstop net today and didn't know if the vendor is buried somewhere on the site but wanted to share them with the membership.  I have three backstops; 1) a 15 oz/yd canvas treated to 23 oz/yd,  2)this vendors ultra duty net and 3)their badinotti net -  all three are in a 10'x10' size.  The badinotti netting will pass anything under about 3/4" in diameter but the tarp and the ultra-duty are good for knocking anything down (wouldn't recommend pointy ended glands).  I haven't put much time on them but the last two are being used to knock down full power throws of steel balls up to one inch in diameter...  The 3/4" opening net works well for the 1 3/8" d.  neoprene balls I use for practicing.  I'll post wear results at a later date.  I use a backstop for trapping ammo I don't want to lose but they are well suited for slinging practice in the city where it's nice not to be damaging your's or your neighbor's property.  I'm also carrying a frame and stop to the classes I'm teaching... it helps if the venues are more urban and we are able to focus a little more on the different throwing styles instead of just "murdering" rocks.  The vendor has a nice looking 7'x8' free standing frame and net stop if you can keep your throws in that size of an area...  stand close that's what I do...

http://sportnetting.com/catalog-flat-panels.htm

I've rigged a frame of EMT conduit and support the backstop net to it with ball bungees...  they work great to dissipate the energy of a throw.  I carry 1" diameter steel stakes and guy ropes for securing the frame against Wyoming's winds.  Otherwise the uprights are integrated into fan bases which I ballast with a bag of sand.  Throwing lightweight (like tennis balls) non-lethal ammo gets tiresome to me and I find the back stop with steel balls to be a great stress reliever (kinda like the two buzzards cartoon where one is saying "patience he__...I'm gonna go out and kill something")