"With the concave facing you..."
Rookie tying question for you: I noticed that many tutes refer to the "concave side" of the feather. As I look at a feather, I notice two concavities. The first is the obvious one: a feather has a natural "arc" to it if you hold it by its stem.
The second concavity that I notice is in the vertical of the feather; in other words, if that feather was perfectly straight (no "arc" in it), the fibers are concave to their opposites along the stem (typically, I notice this in the duller side of the feather). It is this concavity to which I've been paying attention.
So which concave are they referring to?
"For the supreme test of a fisherman is not how many fish he has caught...but what he has caught when he has caught no fish." - John H. Bradley