Why google material design says: "Material never bends or folds."

Question

I read from material design that material never bends or folds. But why? While it is so interesting, delightful and a really nice animation specially in reading books apps?

What's its problem?

Thanks

Answer 1

Just a note to other answerers: If something is a certain way just because they "say so", you are following horrible design. Good and proper design has meaning and purpose to every rule. This is otherwise misrepresentation. Just because someone says "we are about design", doesn't mean it's true. ;)

Why does Google say that material does not bend and fold? For the same reason that they say "Material is not necessarily flat, though it removes unneeded complexity" and that "animations are there to show where things are on screen" among other similar phrases.

They want everything on screen to have meaning - to have purpose. This is very much so the mentality of MD and a very large reason why many things are the way that they are.

Think of it this way - my mother does not know how to use technology. I've been trying to move her to Lollipop because of this reason, MD - when done properly - is designed so that the user can figure out things on their own without instruction because of cues and natural habits in one's brain (see Egoraptor's Megaman Sequalitis for a decent understanding of what I mean). This allows the user to feel smarter than if you shove them in front of an non-understandable system with an instruction book and cuts out that middle man. By adding folds and bends, you are adding symbolism where there does not need to be. If a fold is done a certain way you can misdirect someone, have their attention elsewhere. The idea is to design for meaning - not for complexity.