The viscosity cup is an important part of making your spraying jobs repeatable. Use the viscosity cup by dipping into your product container and timing the flow until it starts to drip. Use the chart in your gun manual to accurately gauge fluid viscosity for the liquid you are spraying. Conversely, by experimenting with different fluids, measure the viscosity to be able to get back to that same sweet spot later. You'll also want to keep notes on the various paints, stain and varnishes. Whe spraying latex paints we recommend TITAN's Paint Mate reducer for best results.