almost all fish caught were taken on dry flies and every one of them measured just short of that magic 20 inches. here we find nothing of the “confirmation” or “blessing,” which terms were introduced later. how do i write a letter to my teacher as an excuse for not doing my homework? and that’s not all of the good news! i find 5/16" id tubing works best for me, but you might have trouble getting it on some of the equipment, so you might find 3/8" id tubing works better for you. 