BANGALORE At a cafe in Bangalore's central district, artist Pavithra Chowdappa doodles on canvas with a marker labeled AIR-INK.
"This is a special marker," she says, making black strokes across the white surface. "It's the only environmentally friendly ink around. And it's so smooth, and nice -- in fact, better than many others in the market -- that one can hardly guess it's sourced from air pollution."
