OK, it doesn't really rhyme when you pronounce it correctly (kor-NAY) but it wouldn't make any sense to say "extra value is what you gay when you make cornets." Or maybe it does make sense to someone, somewhere and then I suspect the meaning would have little to do with baking.
Making cornets, or paper piping tubes, is a valuable addition to your baking and decor repertoire for two reasons that I can currently think of:
(1) they are terribly easy to make, when you remember how to make them,
(2) they are fantastically handy when you have run out of piping bags,
(3) and they give you far more technical precision than a sloppy pastry bag and piping tip.
I could think of three things. I lied.
This is where I find them irreplaceable: when you have to pipe a multitude of colors. They are compact, disposable, require only one accessory (parchment paper) and adjustable: just cut the tip for a larger opening.
Wait. How many reasons do I have now? Oh wait, it's great for piping chocolate, white or dark, because it's microwavable. If the chocolate hardens, just zap it for a few seconds.
Cut a triangle from a piece of parchment. Label the corners A, B and C
Tuck "A" under, towards "C" so that
The tips line up
It's already looking like a cornet!
Wrap "B" around and tighten the cornet up to form a very tight tip
Tuck the ends inside the cornet to seal.
Get ready to pipe!