I shot the entire sign with a Matthews orange, background letters, beveled edge and sides, that matched 1-shot orange. I then used a two part table top epoxy tinted with the 1-shot and poured on top of the flat letters. It's self leveling so it flows out to the edges and domes up just enough to look rounded. It sets up looking like glass. After it was good and cured, I poured the self leveling epoxy onto the background and let it set up to a sticky consistency, then poured on the black smaltz. Let it set up overnight and that's all there is to it.
It's common to use Smith's blending cream to adhere the smaltz, but prefer using the table top epoxy.