Originally Posted by ArmsHeldOut
The mesh skin itself is actually a thin layer that was stretched over the MOS bodysuit before the remaining foam-latex elements were affixed.
And yes, Spider-Man's movie costume certainly is incredibly similar to the one depicted in the source material; that's a fact. I think Spidey's look translates much better on film as is (with little need for alteration) though. Superman's outfit, on the other hand, required a modern update. I don't care for the "desaturated colors" and piping around the torso and legs, but everything else is pretty spot-on. The mesh skin (or dimensional chain-mail texture), in particular, gives the suit a very sleek appearance in my opinion.
Binning the trunks were a sensible idea.