I had trouble with this but have it working now. The freetype, cairo and quaternion rotation matrices line up in the "Good Glyph3" drawing with a couple of reference planes. That way you can rotate a cairo object in 3d without changing anything within cairo. This also is a big help in 3d drawing. Many 3d operations can be built on top of what cairo already has since the 3d gets mapped to 2d which cairo is already good at. Also there is no need to touch all those 2d matrices that cairo already uses. https://github.com/cecashon/OrderedSetVelociRaptor/blob/master/Misc/cairo_drawings/freetype_gtk1.c Eric