Is there any way to thin he paint to make it translucent rather than solid (or opaque)?
No, there isn't any method I know of. Basically you would be reducing the "solids" content of the paint to achieve this. I suppose you could try mixing in some glaze or an extender like Floetrol, but, I don't know that it will make the paint more translucent. Anyone got any ideas?
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Haven't tried it, but accordig to the website, it comes in 3 different opacity levels. Just track down the "sheer" and you don't have to play junior chemist. If you already have 10 gallons of it that you can't return, maybe try the glaze.