I have finally got my cabinet painted with oil based rustoleum, semigloss black.  4 coats on top of 3 coats of kilz oil base primer on MDF.  On the black, sanded with 400 grit sandpaper between coats.   I am very happy with the smoothness of the paint.  One question however, it seems that the paint is still somewhat easily scratched.  It has had 2-3 weeks of dry time and I noticed I have marked it up in several places just working on and around it.  I plan to get artwork, however I may not get a whole covering, and just have several pieces of artwork that are individually installed.   Has anyone had any luck using a spray based lacquer or some kind of protective coat, or is this going to open up a bigger can of worms?   Appreciate anyone's input that has maybe tried this and what your thoughts were. 
Thanks..