This Batman emblem is 65 by 38 studs. The black and yellow background is three plates thick and has 526 plates. The Bat and a stud width edge around the yellow is an additional layer of 180 black plates.
This Ultimate Spider-Man emblem is 72 by 81 studs. Unlike the Batman and Superman emblems it is perfectly flat. Itís three layers thick and has 1087 plates; the spider uses 279 of those.
Designing this was a lot more work than the others. The image I had was a small bit of a desktop wallpaper and rotated; after rotating it upright and converting it to LDraw it was very unsymmetrical; I ended up doing a lot of editing to get the left legs to look the way I wanted, then wrote some code to create a mirror image for the rght side.