I wondered the same thing about Rorschach’s mask the first time I read Watchmen, but it hadn’t occurred to me that the problem could be solved in the way you describe. I occasionally see stories about fabrics that have some sort of active electronics or could even be used as displays; some kind of convergence of those fabrics with e-ink technologies would have all kinds of interesting applications. Imagine: you could just download a T-shirt design from CafePress, for example.

It’s kind of pointless to speculate about how these things work in the Watchmen universe, though, because any “magical” technology can just be attributed to Dr. Manhattan. If he can manipulate matter at an atomic level, that basically means that anything possible through nanotechnology — even theoretically — is something he can do with a wave of his hand.

And who knows what his limits are? Until we get an explanation of what an “intrinsic field” is and what it does, anything’s possible.