Abstract: A layout instrument for constructing the two-dimensional sheet pattern which defines a cylindrical article having longitudinal elements of varying lengths, each of which are parallel to the axis of the cylinder, wherein an oblique plane passes through the cylinder and intersects the base plane thereof at an acute angle. The instrument comprises a calibrated miter scale having a series of equally spaced subdivisions which establish the length of the longest and shortest elements of the cylindrical article and a calibrated layout scale having a series of spaced points each of which establishes the length of one of a plurality of specific, circumferentially spaced elements of the cylindrical article.