New raster-based printers form character patterns using carefully designed matrices of dots. It is desirable to be able to use fonts designed for one printer on a different machine, but to do so the dot matrix patterns should first be scaled to the second printer's resolution. If the scaling is carried out as a simple interpolation, however, severe degradation in the appearance of the characters may occur. A new algorithm reduces such degradation by recognizing attributes associated with print character quality in the original patterns and then correcting the scaled patterns in order to maintain those attributes. Attributes that are detected and preserved during scaling include local and global symmetries, stroke width, sharpness of corners, and smoothness of contour. The method has been used both to scale low-resolution fonts to a finer representation and to reduce the scale of high-resolution photocomposer fonts for output on an office-type printer.