Build your Best Batman Costume (using movies)

Instead of a cape, you might try a mist. Call it a nano-bot shield or something. Batman disappears into the night, because he has a controlled cloud which makes him vanish into the shadows or allows him to "puff up" his image (like the Balrog in the movies, like a Gila monster IRL) in those moments when he needs to look tougher. This would give plausibility to his inexplicable ability to disappear as anyone he is speaking to is mid-sentence in conversation with him. In some moments it could look like a cape, in others wings, in other moments tendrils or exaggerated limbs.

This is just a quirky thing, but if you stop the following clip at 1:45 (and again at 1:49)... Batman is shrouded in shadow and you only see the glint of one of his eyes ... don't know why, but in this one shot he reminds me so much of Adam West in the old TV costume.

Also, this would fit the "bat" mythos in that our other notable "bat man" (i.e., Dracula) also has a portable mist that veils him and teleports him. The association here is loose, but it fits. And Batman needs a world in which he can emerge from the shadow, strike, and then disappear. A rubber cape just does not accomplish this in a modern city.

Since Batman is the one "super" hero who must remain rooted in reality (since that's his schtick that separates him from super-powered heroes), all his tools have to be explainable and, at least, potentially possible. Silver & Bronze Age Justice League stories aside, Batman can't teleport. He has used smoke bombs to create mist to great effect.

He can do a lot of stuff he does (like seemingly disappear when someone turns their head for a second or be able to move silently while wearing a cape) due to years of practice of various Ninja-type, martial arts skills - which are all about silence, distraction & subterfuge.

In this sense, Bale's "felt" cape probably made more sense as it would be lighter and quieter - but the look of the material (which looked like felt) took away the whole Bat aspect from his look; with the cape filling in for "leathery" bat wings.

P.S. I think Dracula could literally turn into mist (among other things: a bat, a wolf, a bunch of bats, a bunch of rats, etc.)