We were among the 350 Somerville artists opening their studios to the public. The city graciously waived permit parking restrictions in support, and for those without a car, a free trolley service provided. Now in its 12th year, Somerville Open Studios is the premier arts event in a city that claims to have more artists per square mile than any other. Even so, the number of artists showing their work at the Center for Arts at the Armory has gotten even bigger.