What you get when you cross a Black bear and a Grizzly bear.
Whitey #1: What do you get when you cross a black bear and a grizzly bear?
Whitey #2: I dunno.
Whitey #1: A Grizzizzle Bear.
Whitey #2: That's not racist fo rizzle.
The use of a napkin to illustrate, design, invent, or otherwise explain some kind of engineering topic, theory, process, or equipment.
Envelopes, hands, and other generally small pieces of paper can be substituted.
Aristotle- How was the napkin ring invented?
Plato- I drew it on the back of a napkin.
Aristotle- Oh, napkin engineering. Toss the fris!