Quirk Gallery on Broad Street has taken the unusual step of branding a line of merchandise to sell in its gift shop. Local artist Billie Wills has designed series of dinner plates with silhouettes of dogs. The series is limited — only 250 plates with Boston terrier profiles have been printed so far — but they are getting ready for a Chihuahua line and two more to follow. The melamine plates are not microwavable, but they are dishwasher-safe and come in a variety of colors. Quirk has also started selling its own greeting cards and T-shirts for doggies and humans.