For objects like dislocations, sufficient information to define a picture can be obtained in 1 min of numerical integration of the Howie-Whelan differential equations describing image formation in the electron microscope. To match this computational speed, the computer line printer is used to print pictures using the half�tone principle. Examples are given, including comparisons with experimental pictures, and it is concluded that when the important information is in the topology of the picture, rather than in precise intensities, a pictorial presentation of the theoretical calculations is valuable.