Don't listen to Opus's recent blog post about Williamsburg paints being "gritty" and coarse ground, because that is a very small percentage of the range. There are four different milling levels, and Williamsburg chooses the best consistency for the particular pigment. The majority of the colours are "very fine ground", next most is "fine ground", and the others are medium or coarse. It's easy to see on the label which are fine or coarse.
I use Williamsburg for very fine detail work on smooth panels and it's perfect for that application. You can also use it for thicker applications, but that is definitely not the only thing it's good for. This is a very versatile paint. It's more important that you pick the correct tube for the particular application that you want.
It is expensive, but it goes way further than other paints because you need so little of it. A pin prick of cadmium red will make orange when mixed with a yellow. It goes so far! The coverage is insanely good.
