The diabolical folks at Evil Mad Scientists Laboratories developed a machine that will draw precise patterns on an egg. The Eggbot has a rigid but adjustable chassis that allows you to mount spherical or egg-shaped objects of various sizes, and rotate them about their axis of symmetry using a stepping motor under computer control. A second stepping motor moves a pen about an axis perpendicular to that “egg” axis, and a small servo motor raises or lowers the pen above the egg surface. The results are stunning:
The objects shown below include golf balls, eggs, Christmas ornaments, and light bulbs. The basic operation is much like that of a printer driver: you import or make a drawing in Inkscape, and use the extensions to plot your drawing onto whatever object you've mounted into the Eggbot. It's all handled through a graphical user interface, and works cleanly on Mac, Windows and Linux.