Michael, I'm not sure, but it looks like he may be working in MoI from an imported OBJ from Photoshop.

gui, if that's the case, please know that MoI exports OBJ great, but it doesn't import OBJ natively-- you have to use a plugin for that. And even if you do use a plugin, MoI is a NURBS based modeler whereas OBJ formats are for polygons. Only simple OBJ models can be imported and converted to splines-- and even then they need to be stitched up to create real solids which boolean appropriately.