IT is smaller than a juice carton and set to fetch a big price at auction.

A tiny portrait by French Impressionist Pierre-Auguste Renoir is expected to sell for as much as £20,000 at a specialist sale in Glasgow tomorrow.

The 1898 work, entitled Etude De Tetes (Study of Heads), measures just 8.3cm by 6cm and is believed to be the basis of one of the celebrated painter’s later works.

It will go under the hammer at McTear’s British and International Pictures Auction tomorrow and Brian Clements, managing director of the city institution, commented: “This is a fascinating work by one of the world’s most revered artists and it is a joy to have it in the auction.

“It may not be the biggest painting undertaken by Renoir but the provenance clearly shows that it is an important work amongst the Impressionist movement.”

Along with contemporaries like Claude Monet and Edgar Degas, Renoir is widely considered to be one of the most influential artists of the late 1800s.