They're an average PCB house, and they like to leave the more difficult features off their "prototypes."

You can't build circuits with 0.8mm or 0.5 mm BGA's with 10-mil traces, nor can you do it without solder mask. Now,the solder mask has to be held to tight tolerances, both in thickness and in width, not to mention registration with the underlying copper.

If I were to build a batch of wire-wrap cards, such as the one on my personal page on 8052.COM, I'd consider them on the basis of cost alone, but if I have to have 0.1 mm traces precisely registered to solder mask 0.2 mm wide and uniformly thick between ball pads, I'm not so sure they're the house for me.

What I'm saying is that you need to read the fine print.

RE