The BGresto stuff is coming along. It's been a huge learning process. Just tested out Four Square and Team One backglasses and I'm really happy with how good these came out. It's been a struggle to figure out which Pantone colors are the "right" ones; the color has to be right and the translucency. But especially with Gottlieb, they re-used the same pantone colors from glass to glass, to a large extent. So i've been tracking the pantone colors, and as we move down the path to the next glass, I can figure out which colors work/look best. Also the back mask layer has had some generational shifts. We're now at a point where i really like how it looks.
I have to admit that GulfStream was one of the first glasses i worked on, and it's had *6* different iterations! The last version darkened the flesh tone colors a bit. I would say the colors are pretty much dead right now.
One advantage to this system is that we can make changes easily. Everything is "on demand" so it's easy to make a change. For example i think the Space Mission glass came out exceptionally well. I compared the BGresto version to the CPR version, and frankly, I think the BGresto version is much better (in regards to color.) Though CPR's is silkscreened, which is an obvious advantage, the colors don't look "right" to me.
Matching silk screen colors must be a headache. On the computer the pantone colors are consistent. But with silk screening the colors are formulated, and a human must weigh out the mix and get it "right." This can't be easy, and causes variations. You can see this on original glasses too. For example on Bally Wizard, I've noticed different flesh tone colorations from early and late serial number games. With BGresto the colors are consistent (unless changed on the computer.)