Samuel Sachs II has announced he’s stepping down as director of the Frick Museum after six years there. “A quirky institution known for its stuffy, family-run board, it now attracts nearly 350,000 visitors a year, up 20 percent a year since Mr. Sachs became director. When he arrived, after having run the financially ailing Detroit Institute of Arts for 12 years, Mr. Sachs said his mission was more one of “fine turning” than of making major changes.”