India, Oct. 10 -- Coffee. For contemporary artists, using coffee as a medium - the drip, the beans, the grounds - is a way of incorporating sustainability in art practices. As a paint, it's somewhere between watercolour and oil. As a texture, it's a visual crunch that few other materials deliver. Giulia Bernardelli, Maria Aristidou, Ilona Zabolotna, Ekene Ngige, Jane Noronha, Ghidaq Al-Nizar have all used coffee to make art. In every case, they make viewers think differently about the beverage.

Nanotech particles. How black is Vantablack, the world's blackest black? Dark enough that it absorbs 99.9% of light itself. Dark enough that a sphere looks like a circle, that objects look like they don't have any depth. It's not paint, it's a lay...