The Paint Bar is a lot of fun, and no matter how little talent you have (I can't draw a circle…read morewithout Powerpoint), you can indeed create a masterpiece (ok, maybe it will only sell for $2 at your garage sale in 10 years, but your very small children will be impressed).
I suggest arriving 30 minutes early, so that you don't get stuck in the line waiting for paints and can focus on importing things like buying a glass of wine. It also helps to be seated near the small stage in front so that you can easily see the example completed painting on the wall. They rotate through a selection of different ones, which are specified on the website when you buy your tickets, so don't pick a class that will paint a lame one like the happy dolphin! Also, you need to see the instructor, who will demonstrate painting an additional example on the stage.
The instructor was quite funny, and fairly clear in explaining the individual steps one by one, although she went pretty quickly. The full 2 hours are necessary to complete the painting, and if you fall behind, you will miss some of the tricks or paint combinations.
If you bring a date, be sure to praise how much better his or her piece is than yours, over and over again. Artists are sensitive, and who knows, you might get lucky later.
If you have talent, maybe your painting will end up in Somerville's Museum of Bad Art, and not in a garage sale!