Just out of curiosity, whenever I see paint ads advertised on tv for Sherwin Williams or Home Depot, they always show the models painting a big W on the wall. And they start in the middle of the wall. What's the meaning of this? I've been painting for 10 or so years, have worked for many paint companies, and was never shown to paint this way. I figured it's to simply get the paint that is soaked on the roller off in the middle of the wall, then to distribute all that paint throughout the wall to prevent drips at the bottom sweep of the roller by the floor boards, but I've always started either left to right, or right to left.