The U.S. Postal Service issued an illustration of a bank swallow by Maryland artist Matt Frey Friday as a stamped envelope, the second in a four-part series of swallows by Frey commissioned by the organization. The bird is the smallest swallow in North America, and adorns the seventh stamped envelope issued by the Post Office this year. A Baltimore native, Frey graduated from Syracuse University's College of Visual and Performing Arts with a degree in illustration in 1996. He has done illustrations for Discover Magazine, National Geographic Magazine and the Smithsonian Air and Space Museum, among others. "This is about the only thing I'm good at," Frey said, "so I'm going to be doing this for a while."