VMS Help SET, PRINTER, Qualifiers, /WIDTH  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /WIDTH=n

    Establishes the number of characters per output line on currently
    installed forms. The width, n, can range from 0 to 65535 for LP11
    controllers, and from 0 to 255 for DMF32 controllers. The default
    value is 132 characters per line.