Last week we showed you a pretty picture of Sudbury-bred actor Chris Evans wearing a long-sleeve T-shirt with the numbers 617 across the chest. Today we can tell you where the Boston shirt came from. Apparently, Evans was modeling a new line of clothing and accessories by Sudbury designers Becky Foley and Melissa McCray. The duo’s Toph Daddy apparel company, which they run with their merchandising pal Hilary Gallagher, features fashions emblazoned with area codes designed for those who want to show off their geographic loyalty. The women have actually trademarked area codes in all major markets so that no one can steal their idea. The 617 shirt made its way to “Fantastic Four’’ star Evans through Shanna Evans, Chris’s sister, who has baby-sat for the designers’ kids. The Toph Daddy women didn’t know that Evans had added the shirt to his regular rotation until they saw Chris’s picture in the Globe. Quite obviously, they were thrilled with the product placement. Chris was recently chosen to play “Captain America’’ in a big-budget adaptation of the comic book.