mouth - small flies!
The headline contains some truth in the sense: When
trout/graylings eat tiny surface-food, they only nead to open their mouth to a
narrow slot and sip the fly in. If one presents them with a fly with a broad
hackle - then they canít suck it in through their narrow mouth.
Vince Marinaro in his book "A modern Dry-Fly Code", 1950 showed how he
solved the problem.
For his famous 'Jassid' he uses:
regular size 16.
short-fibred black cock-hackles wound as a palmer up over the shank, and
then cut on top and bottom, so that the fibres only point out to the
from a Jungle Cock tied down, so it covers the shank.
© Preben Torp Jacobsen. 'Flyleaves', 1996.
It floats perfect in the surface, and by this imitates the small, black
insects caught in the surface.