Since I was a high school kid, I have been mildly obsessed with finding the perfect indicator. Back then I remember we hollowed out balsa wood struts from left over bits of our model airplanes. They were small sections of square bar, and we used a needle to make a small hole through them lengthways, so that we could thread them onto the leader. Then of course they had to be painted and varnished for durability. As a school-kid I was excited that this idea made it into print. The downfall of these things is that you had to position