SAM Toft will be signing copies of her memoir, One Man And His Dog, on Saturday in her first visit to the Braithwaite Gallery in York.

The popular South East coast artist will be in Mark and Anne Braithwaite's gallery from 11am to 2pm, when she had planned to perform her Drawing To Music skit too but unfortunately an eye infection has intervened.

Sam is on a signing tour to promote a book that celebrates her artwork so far and features never-seen-before sketches from her studio. It recounts her story of a bohemian childhood in the 1960s and 1970s, followed by struggles with depression, loss of direction and finally seeking salvation through art and a love of her vocation and dogs.

One Man And His Dog features more than 200 images, ranging from sketch books and early work to illustrations and puppets, as well as a chapter devoted to Sam's most beloved creation; her imaginary friend, Ernest Hemmingway Mustard, where she reveals the inspiration behind Mr Mustard, his well-upholstered wife, Violet and their grumpy, overfed Jack Russell terrier, Doris. Previously unseen images and drawings are included too.

Sam, who lives in Brighton with her two dogs, is one of Britain's best-selling artists, with her posters, limited editions, calendars and greetings cards having netted millions of pounds in sales over the past 15 years, while her original works sell from £450 to £7,000. She created the Small Dog painting that was a best-selling image in IKEA for two years running and continues to sell more than 150,000 posters per year worldwide.

"I found the writing of the book extremely challenging, firstly because I'm not a writer and secondly because I'm writing about childhood, when you have to get into that feeling of how you felt at ten," says Sam. "I worked with a screenwriter friend of mine and did seven drafts, and after the seventh I said it would kill me to do another, but he kindly said 'That's fine'!

"The best passages, he said, were the ones that were the most difficult to write, stepping into the shoes of childhood, not because I had a terrible childhood, but because they were poignant memories and some of the people I mention are dead."

Sam is candid about having struggled with depression. "It's incredibly difficult and that's partly because of the stigma attached to it. People think it's just sadness but it's not like sadness at all," she says. "It was through art therapy that I was able to address depression in my 20s.

"With my artwork, if you look at one of my paintings, I think I teeter on the brink of twee: it's quite naive and easy to look, and I know less understandable artists are more respected but I see my works as comfort blankets, where when someone dies, they do walk off into the sunlight. The images are childlike, rather than childish.

"I'm asked why nothing bad happens in my work and I say real life is bad enough already."