Quoted from sudsy7:
Gotta ask - why would CPR use semi-transparent ink knowing that playfield wood "character" is going to show through it?
I was summoned to come here and answer this very excellent question, so it could be put to bed. So I will. It's worth chiming in for.
Logically, one would think that it's possible to stay away from semi-transparent inks, and "just use opaque" ... but unfortunately it's not that simple. So I'll take a moment to explain:
The two colors in question are Pantone GreenC, and Pantone 300C ... and with all spot colors in the industry, are made up of some combination of the 18 primary colors (the Pantone Matching System series) offered in inks today.
This means every spot color we can screen are mixed from 18 colors. We keep the entire Matching System set on the shelf, in gallon cans, to make our inks from at all times.
Those 18 Matching System colors are pure in the cans, meaning they are completely tint. There is no "white base" in them - as that would "whiten" or dilute their pop / strength. This puts the 18 Pantone Matching System colors way out on their respective points on the color spectrum (for maximum gamut), each pulling in a specific different direction. Being completely tint, no base, they are like liquid color - like a candy apple coating - and are semi-transparent.
So let's start with Pantone GreenC ... the recipe for Pantone GreenC *IS* Pantone GreenC ... as GreenC is one of the Matching System series. You don't need to add or take away anything from it. It's straight out of the can. So in the case of EBD, it gets printed to the playfield as-is. Adding white to it, to opaque it up, will fade out the GreenC and make it lose pop and look completely incorrect. GreenC ink sitting on top of a pure white base (the white ink on the wood underneath) is exactly how you achieve GreenC in printing. That's how you "hit" the color, dead-on.
Pantone 300C is a medium blue that is very very common in pinball. It's recipe is a mix of 81.25% Pantone BlueC, and 18.75% Pantone Reflex BlueC ... no base/white added. Printed on top of a pure white base, to achieve the final color.
Swatches of both (just taken as examples from Google images) are below. Monitors may vary.
In conclusion, some colors, based on where they sit on the full gamut, contain near zero (or actually zero) base/white in them, in order to hit those "poppy" colors on the far edges of the color gamut. That is why if those come up, a color or two on a playfield, you can see "thru" them to the white-on-the-wood below. Most of the time, colors on playfields are more towards the middle of the color gamut, and have 10%, 20%, sometimes 50% white(which is opaque) base in their recipes. GreenC and 300C do not.
Just so everybody knows, Bally went through the same thing, with semi-transparent inks (I mean, they had to, just like us) on every original EBD playfield out there. We have an NOS EBD playfield here, Kruzman clearcoated, as a loaned specimen... never had a ball played on it in it's life. This NOS playfield you can certainly see "thru" the green and blue inks. It has some little nits/hickeys showing through from the white layer and wood underneath... but moreso the completely visible vertical-sanding grooves in the woodgrain show through the most (where ours don't have that, because we sand with finer grits than back in the old days). Photos attached below. No matter how or who does EBD playfields, both those colors are semi-transparent.
Hope this helps explain the logistics of this stuff. If it were only so simple.
Classic Playfield Reproductions
EBD NOS - clearcoated
EBD NOS - clearcoated