Thought you TGM enthusiasts would enjoy seeing how I "locate" the Plane Line with video. I position the camera "on" the imaginary Inclined Plane, looking parallel to the Target Line. I "mark" the Inclined Plane with a drawing tool. When the clubshaft adheres closely to the marked line, then the Plane Line will be within a few degrees of Square to the Target Line. That's the case with this here example.