The blue-grey sky awaits Day's radiant surrender to Night. Radha, dressed in red, is in the courtyard gracefully tempting a peacock with a many gemmed necklace.

The head and neck of the peacock and the complexion of Krishna looking on from a window above are of the same tone as the sky. The 18th century Kangra miniature painting is one of the 262 works in the soon-to-be-launched Painting Gallery of the Indian Museum. "The gallery is set to open on May 18, the International Museum Day," said Jayanta Sengupta, the director of the museum.

The Painting Gallery, with a history of intermittent closures, had been totally locked down since 2014, when all the works on display were sent for restoration and preservation. Instead of the damp rooms on the third floor of the heritage building, the new gallery, spread across 512.107sq ft, is being set up on the first floor.

"I planned the gallery in detail with 3D models and colour schemes. These are rare and priceless works, so all efforts are being made to ensure they are preserved and protected," curator Nita Sen Gupta said.

From the meticulously detailed Siberian Crane by Jehangir's court painter Ustad Mansur, which is said to have prompted Abanindranth to seek his own Indian painting idiom, to Abanindranath's later creation Abhisarika (a young woman luminous like a moonbeam flitting to a nocturnal rendezvous) - the gallery will showcase some amazing examples of Indian painting.

As many as 17 Persian paintings will be on display in the gallery, as opposed to only four or five in the earlier one.

Among the exhibits are leaves from a folio of The Shahnameh or The Book of Kings, written by Persian poet Ferdowsi in 10th century, and the lavishly illustrated manuscript Khamsa-i Nizami by Nizami Ganjavi.

"The collection spans painting styles over a period of over 500 years. Along with the collection of ancient sculptures and archaeology, it completes a truly encyclopaedic range of Indian art," director Sengupta said.

One of the 35 Mughal paintings depicts a young Akbar marching out in regal splendour. A study of an emaciated horse by Basawan, who illustrated the Akbarnama, catches the eye as do Dara Shikoh on horseback.

The Deccani Ragamala painting is represented by 17 pieces dedicated to Raga Malkauns, Raga Dipak, Raga Megha Malhar and Ragini Todi, among others.

There are 23 Rajasthani paintings, some of them studded with pearls and emeralds, from Mewar, Bundi, Marwar, Bikaner, Jaipur, Kota, Kishan Garh and Ajmer. Krishna Lila is the subject of the two ancient Pichwai paintings.

Twenty-seven rare paintings by Nainsukh and other Pahari painters offer illustrations of Mahabharata, including tales of a child Krishna.

There are quite a few Company School or Patna Kalam paintings on mica and ivory by Iswariprasad Verma and Mahabir Prasad Verma. From Bengal are 102 paintings: 12th century palm leaf manuscripts, Kalighat patas, lithographs, and works by Abanindranath Tagore, Nandalal Bose, Rabindranath Tagore, Gaganendranath Tagore, Sunayani Devi, Bamapada Banerjee and Atul Bose.

The works on display are, however, a fraction of what remains unseen in the museum. "When I saw the entire collection, I felt like Alibaba in the cave. It's a treasure trove," said Ratnabali Chatterjee, expert consultant for the gallery.