The printing and displaying of pictures as stereo pairs has been widespread for a long time, and yet it is still a common experience that published stereo pairs can be difficult to fuse, can cause eye-strain, can give a false or confusing sense of depth, and are sometimes even front-to-back inverted. This short note is intended to describe simply how to minimize or eliminate these common problems. The method is to match the focus and the convergence cues at the viewer's eyes, and to calculate the geometry reliably and accurately to better than the crude approximation now almost universally in use. Experience has shown that stereo so printed is acceptable to many people who normally cannot use the technique, and that a more secure sense of positioning and depth can be achieved.