Can you mix latex satin exterior and latex matte flat interior?

It's not recommended to mix latex satin exterior paint with latex matte flat interior paint. The two paints have different formulations and finishes, which can lead to adhesion issues, uneven appearance, and varying durability. If you need a specific finish or color, it's best to choose a compatible type of paint designed for the same environment and application. Always consult the manufacturer's guidelines for optimal results.