I would not use "Chassis black" on anything. I concur with Jim, about 90% gloss. Remember that today's paints have had 40 years of refinements to make them glossier. The "gloss black" you will get at the paint store is formulated for maximum shine because they assume you are using it on the exterior of a car. If you want it to get just the right sheen of gloss you need to SLIGHTLY dull it down some with some flattening agent.