In my previous video, “Mixing Paint & Filling a Spray Gun, Small Shop Spray Painting Part V,” I simply guessed when I thought I had it thin enough. View at: In this video, I show you how to measure the viscosity of paint, using a #4 Ford Cup. This, along with some 2.0mm gravity feed guns, is available on my Amazon store at or directly at I selected the guns simply by reading the star ratings and honed in on the ones that people liked the best within the price range of not over.00.