Large Sign Graphics

I have to do a sign for a convention 2' x 16' and I showed a mock-up to the client. They liked it, but now I have a problem at actual size. I did a manual type effect, one we used to do way back when I worked on a flatbed camera (Marron-Carrol) where you had a color layer, a white layer and a black layer and you stepped them to create a highlight/dropshadow effect. It reads fine small, but will it look funky large, and does it make a difference from 15 feet plus away? I didn't think doing an emboss would give the same look.

Thanx for the suggestions, I know there is a whole set of skills for doing graphics on a larger scale.

wms out.