Stipple is a kind of pixle-toggling using a bitmap. Gnus uses this, for example, to insert a wonderful Gnus into the splash screen.

To illustrate this, the following code fragment creates a Face with a stipple consisting of a 2x2 bitmap. The top right and the bottom left corner are set. Tiling this bitmap gives a chess-board bitmap.

 (make-face 'foo)
 (set-face-stipple 'foo (list 2 2 (string 1 2)))

The following the inserts the string foobar into the buffer and adds the stipple to the first three characters. Evaluate this in a buffer without font-lock (as font-lock removes all non-font-lock TextProperties immediately).

 (let ((str "foobar"))
   (put-text-property 0 3 'face 'foo str)
   (insert str))

Apparently stipple is unsupported on Windows[1]. – AdamKerz

Also does not work with emacs-mac-port () on OSX (I have not tested the Emacs NextStep OSX build.) – Jason Milkins

It should work on emacs-mac-port as of this change in 2019-Mar: [2]AmitPatel