Which do you prefer for the lining of your fly box ? Latest edition of TF reckons foam locks moisture in and rusts hooks, while sheepskin will allow the air to circulate and dry them out. Now, I'm not suggesting that the experts at TF are in any way clueless, but isn't the opposite true ? Won't rust spread through sheepskin fly patches/lined boxes like Sh@@e through a goose?

Sheepskin is less dense, therefore you would expect that air would be able to circulate around the hook and allow it to dry.

Additionally, I have never seen a rusty sheep