Abstract: A cutter device comprising: a rigid rectangular support frame, including an elongate guide bar for positioning the frame at the edge of a web article; a transversely extending slide bar joined to and extending across a midportion of the rigid rectangular support frame, secured to the elongate guide bar; and a knife holder assembly which is transversely slidable on the transversely extending slide bar. The knife holder assembly comprises a main body member which is transversely slidable on the transversely extending slide bar, and which may be locked in a selected transverse position, with a knife blade secured on the main body member for engagement with a transversely inward region of the web article.