After posting about PowerPoint’s difficulties with circles and straight lines, I’ve now found it also has a problem with patterns and zoom. See the first image, where the stippling of the two lines is exactly parallel, viewed at 400% zoom. Also note that the arrow is pointing from one “stipple” to another, which is more aesthetically pleasing than having the arrow stuck between stipples, or half on one stipple.
Then see the next figure, where the same scene is viewed at 200% magnification:
Now, the base of the arrow is only half on one stipple. Not what I was seeing before. Why would I bother to look at a higher magnification if what I’m seeing at that magnification is not representative of the final image? Absolute shambles.