That it was the world's first independent school of painting which dealt exclusively with the commoner and his lifestyle also helped Patna Kalam paintings gain in popularity. The subjects of these paintings had always been the common man and his mundane routines. It's basically a miniature form of painting which has, because of its unique style and form, occupied separate shelves at art galleries in London and museums in Prague.
But unfortunately, unlike the world-famous and more acclaimed Mithila paintings, Patna Kalam has not received its due share of attention. Patna-based artist Amaresh Kumar insists and adds that the eponymous painting was far superior to the more popular Mithila paintings. But "Mithila paintings were marketed in an organised manner both at home and abroad. Also, Mithila painting is a folk form which could be easily transferred from one generation to another."

Some famous painters of Patna Kalam were Sewak Ram, Hulas Lall, Shiv Lal, Shiva Dayal, Mahadeo Lal and Ishwari Prasad Verma. The painters used to extract colours indigenously from plants, barks, flowers and metals. Generally they painted on glass, mica and ivory sheets. These paintings are painted straightway with the brush without using the pencil to delineate the contours of the picture.

This technique was commonly known as Kajli Siyahi. The features of the figures of these paintings are characterised by the pointed noses, heavy eyebrows, lean and gaunt faces, sunken and deep-set staring eyes and big moustaches. The principal centres were Patna, Danapur and Arrah. One of the important characteristic of Patna Kalam is that usually they do not paint any landscape, foreground or background. Another unique feature of this school of painting was the development in the shading of solid forms.
Since Independence, the Patna Kalam was on a gradual decline, with no new faces coming forward to carry on this ancient tradition. Ishwari Prasad Varma was the last known practising Patna Kalam master artist in India.