What is RTF ?

I guess I need to get out more.

It is the type of finish...RTF is "rigid thermofoil"

RTF is a type of plastic (from what I can tell usually PVC Vinyl). Many paints will not adhere well to plastics. Even if you are successful (test test test, first) with something like Fusion, RTF cabinets tend to delaminate over time or shrink with heat exposure.

What I am saying is that you should consider this a short-term solution.