Striking use of cutaways on the blade and handle.
The artistry of the above folders strikes me as positively Elvish. I can imagine Legolas pulling one from his pocket in The Lord of the Rings.
Dagger à la d'Estaing
The type of knife shown above, in which the blade folds into the handle but extends beyond it so that the knife must be kept in a sheath, is called a "dagger à la d'Estaing," after Count Charles Henri d'Estaing, who came up with the idea in 1780. The design was popular enough to be manufactured and sold throughout the 19th century. It was intended as a hunting knife for dispatching game as well as other camp chores. Knives of this style were available in America and were commonly called bowie knives.