'It's horrible!': Hockney muse recoils at portrait of her as older woman

To say Celia Birtwell is not a fan of the latest portrait of her by David Hockney might be an understatement.

“Oh it’s horrible,” she said, peering quickly and reluctantly at a smartphone picture of a large drawing on display for the first time at the National Portrait Gallery. “He says, ‘Celia you look very wise.’ I thought, ‘I bloody don’t’.”

Birtwell has been Hockney’s most famous muse for more than 50 years and it has been a joy and an honour to sit so many times for him, she said.

But recent drawings are more difficult to look at. “We all get older, whether we like it or not, and we don’t look like we did when we were 25 or a teenager … You can’t go wrong at that age if you’ve got a nice face. When you get older you are more aware of time.”

She didn’t blame Hockney, she said. “It’s life! One gets old. It is a reality of who you are and what you look like now.

“We only ever see ourselves in the mirror, we never ever see how we really are. He sees you as you really are.”

Recent drawings by Hockney of three close friends: Birtwell, Gregory Evans and Maurice Payne, are to go on display at the first major exhibition of the artist’s drawings for 20 years, opening to the public on Thursday.

Related: Hockney muse Celia Birtwell: 'Nobody else has ever asked to draw me'

They are the final room of the exhibition. “The cruel room,” joked Birtwell. “What are you going to do about it? You can’t change age.”

The portraits were drawn last year in Los Angeles and Normandy, where Hockney is currently living, and were made with a walnut-brown coloured ink favoured by Rembrandt.

They were informed by all the sittings done previously, which in Birtwell’s case is in the hundreds.

Birtwell, a textile designer, first sat for Hockney in 1969 and is the subject, with her fashion designer husband Ossie Clark and their cat, of one of his most famous paintings: Mr and Mrs Clark and Percy (1970-71).

The NPG show deliberately seeks to show the passages of time and has a whole room full of younger, and in her eyes more glamorous, Celia drawings.

It was wonderful to see them together, said Birtwell. “I am deeply honoured because there is nobody finer than David. He is an amazing artist and I’m very fond of him. He is a good pal of mine as well.”

There are around 150 works in the NPG exhibition, including self-portraits he made as a teenager in Bradford, drawings of his mother Laura, and a painting of his parents going on display for the first time since he made it in 1975.

Nicholas Cullinan, the director of the NPG, said the drawings on display illuminated “Hockney’s distinctive way of observing people around him, creating an intimate visual diary of the artist’s life”.

To coincide with the exhibition the commercial gallery Annely Juda Fine Art is staging a show of recent portraits of people including Birtwell’s granddaughter Scarlett Clark, the singer Ed Sheeran, and the neuroscientist Colin Blakemore.