Hindu musician playing the tabla (drums) with typical black spot made from a mixture of gum, soot and iron filings, West Bengal, India, Asia

Man covered in black soot, Ati-Atihan Parade along White Beach, during the annual Ati-Atihan Festival, Boracay, Aklan, Philippines, Southeast Asia, Asia

Portrait of two men, one masked, the other with soot smeared on his face during the Ati-Atihan Festival, an annual feast in honour of the Santo Nino, Boracay, Aklan, Philippines, Southeast Asia, Asia

Boys, with soot smeared on their faces, in the parade along White Beach during the Ati-Atihan Festival, an annual feast in honour of the Santo Nino, Boracay, Aklan, Philippines, Southeast Asia, Asia

Patterns in carbon on the fire glass of a stove door

Carbon patterns on fire glass of a wood burning stove

Patterns in carbon on the fire glass of a stove door

Portrait of a miner, Tower Colliery deep mine, Hirwaun Glamorgan, Wales, Great Britain, Europe

Chimney sweeps standing on roof, dome of New Synagogue, in background, Berlin, Germany

Sign, particulate filer, For the sake of the environment, this vehicle is equipped with a particle filter

Open fireplace in a Hessian farmhouse, Hessenpark outdoor museum near Neu-Anspach, Hochtaunuskreis district, Hesse, Germany, Europe