Yes, and no. The terms are often used interchangeably, but quarter sawn refers to the milling process of cutting a log into quarters and then cutting boards out against the grain. Vertical grain refers to the grain pattern itself, and can refer to boards that are not technically quarter sawn. In the case of quarter sawn, bevel-cut clapboards, both terms are correct, because the logs are milled from the center to the edge like a pie, resulting in all of the boards having that vertical grain.