"I knew an auto mechanic once who all he had in his toolbox was a screw driver and hammer. That is all the tools he had and had fixed cars his entire career. What that has to do with paint brushes - well you could use one brush to do everything, but you might consider the end results before you begin. This "mop" as I call it works well with an airless (low-pressure). After meeting the expected prep requirements I spray on the stain and while it is still wet use this brush to massage or work the stain into the wood. The brush size woods well on siding and decking, not so much for trim."