Chelsea’s Hudson Franklin gallery plays host to a three-day exhibition of offset lithographic posters, a medium “often considered outside of the high-art spectrum.” Organized by Matthew Spiegelman, “Offset” features new works by ten artists printed on the “same large multi-plate presses used to produce magazines, take-out menus, and calendars.” The show opens from 6 to 9 tomorrow night through Saturday at 508 West 26th Street, Suite 318. Each poster, measuring approximately 39” x 27”, is available for $100 from a limited edition of 200.