Hello Geert,                                         

  GH> xsetbg is part of graphics/xli and supports tiling (in
    > fact it's its default when an image doesn't fit the
    > screen).                                           

Installing xli enabled "bsetbg -t stone.png" to tile a
tasteful stone texture into the root window.  I will look at
xli's other options and perhaps learn to use it directly.

Many thanks,  
  - Andy Ball.