Im trying to make a supergirl character, but I cant figure out how to apply the S shield to V3 catsuit. Any advice?

Create a template of the catsuit in UV Mapper, and use that to make your own custom texture in some paint program that allows layering.
DPH

Just FYI, DAZ has a template already made for the cat suit, here, 'bout the middle of the page.

What DP said...Take your template...make a copy of it, don't use the original or you will lose it in an unfortunate accident, into Photoshop (for example), put blank layer on top of it and place the shield where you want it and then merge the visible layers and save.  Theoretically when you put the suit back on the model, it should conform with the boobs and look like you bought it that way. (sorry, comical tackiness)  The catsuit is actually easy to work with, even with my limited knowledge I've altered the suit for many different things just playing around.

Ever heard of a "node mask"? It should work perfectly, provided you have P5 P6 or P7. Check out the tutorial: http://www.rdna3d.com/Tutorials/Poser6/ColorMasking.html

Yes I use masks all the time. It allows you to put a large texture of just the logo on the suit. Basically you adjust the uv position on the texture and make it no tile. Its also great for adding hires texture parts to the body like high res nipples or lips.

they probly have some supergirl things at diane's site (animotions). they may be for p3 or p4 or v1/2, but ya might get lucky.

There's a Supergirl at the site in my sig line.  The textures include an S-shield which you can adapt if you need to.

Thanks everyone