Peggy Macrae was the household name 'supermodel' of her era who featured in the nation's most expensive painting

She was the charming, witty Edinburgh beauty "who had the rare gift of complete grace which made her every movement interesting".

Now, a portrait of the early 20th century artist's model Peggy Macrae could fetch up to £300,000 at auction.

Macrae was painted by the Scottish Colourist artist Samuel John Peploe in his studio in Edinburgh's York Place around 1908.

The impressionistic oil painting "The White Dress" shows her in an elegant pose, her head slightly upturned, gazing out from the canvas.

Peploe's striking masterpiece is expected to draw international interest when it goes under the hammer for the first time ever during Sotheby's Modern British & Irish Art Sale in London on November 23.

Thomas Podd, Sotheby's Scottish Art specialist, said the portrait was "one of the best" the artist ever produced.

He added: "The model is Peggy Macrae, who sat for Peploe quite a lot in the early period of his career. Peploe had a number of models but Peggy was his favourite.

"It's an extraordinarily important picture by Peploe, and one of his greatest ever portraits. We are absolutely delighted to bring this to the auction market for the first ever time. I think many serious collectors will be motivated to bid on it."

The White Dress featuring Peggy Macrae, painted by Samuel John Peploe around 1908

Peploe, born in Edinburgh in 1871, was the eldest of the four Scottish Colourists, who also included John Duncan Fergusson, George Leslie Hunter and Francis Campbell Boileau Cadell. The foursome went on to set a new standard for the use of Scotland’s unique light, landscape and inhabitants.

The Colourists were never self-indulgent and firmly were of the opinion that the art came first, always ahead of any other considerations.

Peploe, one of the purists, painted "The White Dress" in his studio in Raeburn House, the A-Listed three-storey terraced house at 32 York Place that inspired his so-called White Period in the early 1900s.

Like a supermodel of her day, the elegant Macrae was well aware of her worth. Artists needing a model would make a beeline for her and she carefully selected those with whom she worked.

It has been said that her striking looks and instinctive feel for presentation -- the angle of a hat, the tilt of an eyebrow -- were in great demand and that she posed so naturally that portraitists commissioned to paint fashionable society women would secretly use Macrae to model the clothes.

A particular favourite of the Scottish Colourists, she also appears in famous portraits by Cadell, while another Peploe masterpiece, "Girl in White", for which Macrae posed, was for many years the most expensive Scottish painting at auction at £506,000.

Stanley Cursiter, the portraitist and Keeper of the National Galleries of Scotland from 1930-1948, in his memoir of Peploe, described Macrae as "a charming, witty, and attractive girl, who had the rare gift of complete grace which made her every movement interesting".

He added: "She dropped naturally into poses which were balanced and harmonious and, better still, she immediately impersonated the figure she was asked to represent."

Within a few years, Macrae would marry and emigrate to America, leaving behind the paintings she graced as her lasting legacy on Scottish art.