Instead of a "guide" can you purchase a throat plate with quarter inch marks? If you use the tape method, you could cut the tape on both sides of the bobbin cover so that when you remove it, the tape stays on the cover. On occasion when I've wanted the marks to extend to the edge of the machine's bed, I've taken a soft leaded pencil and made little marks along the quarter inch line right on the machine bed. My machine is quite shiny and smooth and the marks come off easily, so it is a short term technique.