Abstract: We present a new approach to the simplification of line drawings, in which a smaller set of lines is created to represent the geometry of the original lines. An important feature of our method is that it maintains the morphological structure of the original drawing while allowing user-de ned decisions about the appearance of lines. The technique works by analyzing the structure of the drawing at a certain scale and identifying clusters of lines that can be merged given an extendable error threshold. These clusters are then processed to create new lines, in a separate stage where different scenarios can be favored based on the application. Successful results are presented for a variety of drawings including scanned and vectorized artwork, original vector drawings, drawings created from 3d models, and hatching marks. The clustering technique is shown to be effective in all these situations.