Faythe Levine and Sam Macon set out to document the diminished but resurgent craft of hand-painted sign making in The Sign Painters. The documentary’s New York premier, tomorrow and Thursday night at Nitehawk Cinema, is sold out. But New Yorkers can meet the authors and scoop a signed copy of the book tonight at Strand. In its pages you’ll meet the unsung artists who hand-lettered the American landscape, like Clark Byers. His “See Rock City” on the roofs of myriad barns throughout the Southeast is familiar to anyone who hails from or has traveled through the region. Or Ernie Gosnell, who was tutored in the trade by a lady wrestler who “tattooed a little bit on the side,” before lugging his brushes from Atlanta to Seattle, ladeling lovin’ spoonfuls of alphabet soup along the way.