The Trico is one of the easiest mayflies you’ll ever tie and one of the hardest to see once it’s on the water. Three tails, a thread body, a sparse wing — a competent tier can crank out a dozen passable spinners in an evening. Then the hatch comes off in late July, you drop that size-24 onto a glassy flat fifteen feet away, and it vanishes into the glare and the foam. Every fix for that problem lives at the vise, and every one of them costs you something. A wing tall enough to track is a wing a hard-fished trout can notice too. So you’re not trying to make the fly as visible as possible — you want just enough to solve the problem in front of you.

In Tying Small Flies, Ed Engle made the case that you don’t always need to see your Trico at all — that a sunken, drowned spinner fished just under the film will take educated trout that have started refusing everything riding on top. He’s right, and it’s worth remembering when the surface game falls apart. But most of us still want to fish the dry, and most of us, somewhere north of forty, have noticed that a clear-winged size-24 spinner at twenty feet might as well be invisible.

First, though: “visibility” means two different things on the water, and the fix depends on which one you’re after.