MacPaint is a paint program for early Macintosh computers. You can see it, and try it out, at the Internet Archive: <https://archive.org/details/mac_Paint_2>.
Its native image file format is very limited, and very obsolete. But a large number of MacPaint files were created, back in the day, and some of them can still be found. For example, there are some at the following locations:
MacPaint has a palette of 38 customizable “brush patterns”, visible at the bottom of its window. The interesting thing is that, at least with the later versions of the software, these brush patterns are stored in the user’s saved image files. But since nobody uses MacPaint anymore, and other software that supports MacPaint file format tends to ignore the brush patterns, it’s easy to forget that the patterns are there.
But they are there, so let’s see what some of them look like. I downloaded the MacPaint files from the locations listed above, and extracted the brush patterns inside. Here are all the unique pattern sets, combined in one image:
There are two standard default pattern sets, each of which occurs in many of the files. I put those two at the top of the image. The rest of the patterns sets are in no particular order.
Technical notes: A MacPaint file contains a set of 38 brush patterns, 8 bytes each. They are usually encoded in the 304 bytes from file offset 132 to 435. I gave each pattern set a CRC-32 identifier, computed from these 304 bytes. Files written by early versions of MacPaint (“version 0” files) normally don’t have brush patterns, so such files were skipped unless they seemed to contain a non-blank pattern.