You're both right. If you are going to paint the wings, then 1/16th covered with light glass is plenty strong. The down side is, it's difficult to keep the weight down with painted wings. It can be done, I've done it myself and Matt K has done it many times, and he is a master at this technique. I actually hit a tree with one that had 1/16 sheeting, laminated with glass and painted....the tree went all the way to the spar, then stopped cold and ripped the wing tube loose from the fuse...taking the fuse with it.....making a nice nose section and tail section, seperated right under the canopy. The wing however, from the spar back, was immaculate......and both panels intact with each other.

But if you're going to use monokote over a built up structure, 1/16 is borderline at best. I use 3/32 and sand the hell out of it.

All that being said, if you do those spars like I showed, 1/16 might be plenty even on a monokoted wing, and you'd save a couple of ounces. But I don't want to be the guinea pig

-Mike