HIS novels have been described as combining a dash of Heartbeat, a sprinkling of All Creatures Great and Small and a liberal dose of Please Sir!.
But whatever Jack Sheffield's formula, it's clearly a recipe for success, with his first book Teacher, Teacher! selling over 50,000 copies.
Now the teacher-turned-writer from Gipton is ready to see his fanbase grow still further with the follow-up Mister Teacher, now out in paperback.
"I think people enjoy the fact that they are feelgood books, which is exactly what I intended," says Jack, who was born Jack Linley in Leeds in 1945.
"I wrote the first one for the baby boomers like me who were young professionals at that time and also for all the thousands of primary school teachers out there.
"But I've had lots of emails from 30-somethings who were at school then and can remember the assemblies, the hymn practice and playing on a triangle."
The books follow teacher Jack Sheffield, the headmaster of Ragley-on-the-Forest Church of England Primary School, based on the North Yorkshire village school where Jack himself was headmaster.
Starting in the late 1970s, they see Jack deal with everything from nits outbreaks to cycling proficiency tests and a burgeoning romance with deputy headmistress Beth Henderson.
Jack the author says the events in the books are largely the fruits of his imagination, though some elements were inspired by the diaries he kept while he was a schoolteacher.
Jack studied to be a teacher in York and during the summers took a job driving a Corona pop van delivering to homes across Leeds.
One of his favourite photos is of him standing beaming in front of his van in Gipton the day England won the World Cup in July 1966.
"It was a great job and a lot of children were very excited to see me. I really do think it helped make me a more rounded teacher because I met people from all walks of life.
"It helped me grow up a bit and was great preparation for what lay ahead."
After qualifying, Jack taught at various schools in Yorkshire before becoming senior lecturer in primary education at Bretton Hall near Wakefield.
"I loved teaching because it felt like I was doing something worthwhile with my life. The children were wonderful and I think that comes across in the books.
"My pupils still make contact and tell me they remember the times when we went camping or built the school pond. We turned out literate, numerate young people and that makes me feel proud."
But Jack may never have become a teacher if it had not been for a chance encounter with a TV and radio legend.
"Jimmy Savile gave me a lift when I was hitchhiking late one night in 1964," he recalls. "We got chatting and he asked me what I was going to do with my life.
"I told him I was either going to be a policeman, a teacher or join the army. He said he thought I would make a great teacher and I should get myself down to the Corn Exchange the next day because they were holding a a recruitment fair.
"I loved teaching and feel very fortunate that I ended up picking the right profession. Jim was right, he definitely fixed it for me."
By then, Jack already knew the difference a good teacher could make.
He credits a schoolteacher at Coldcotes Junior Boys School in Leeds called Mr Rose for first awakening his interest in books.
"He read White Fang by Jack London to the class and I asked him how I could become a writer. He said, 'Go to Compton Road Library and read everything you can.' So the journey began.
"My mum, Margaret, bought me my first book for Christmas in 1953.
"It was Five Go off to Camp by Enid Blyton and I read it every night under the sheets by the light of my three-colour torch and life seemed complete.
"It was only in later years that I realised how difficult it must have been for my mother to afford that book.
"She made me promise that one day I would turn my teaching diaries into books and I'm keeping that promise."
Having duly completed his first book, Jack's big break came three years ago when he travelled to London to attend a writers' conference and gave a copy of his novel to a London literary agent.
The following year the agent secured a contract for Jack with Transworld Publishers and his third book, Village Teacher, is due out in January 2009.
Jack, who has just turned 63 and recently moved to Hampshire with wife Elisabeth, says he would like to write a book a year until he turns 70.
That would mean there would be more than enough adventures to turn his books into a television series, with some rightly suggesting it would make perfect Sunday night fare.
But Jack himself, though flattered by the suggestion, is just glad to have enjoyed the success he has had and is not looking too far ahead.
"It's a sentimentalised Yorkshire I write about but we all tend to look at things through rose-coloured spectacles. I am just delighted that people seem to like it."
And despite the change of career, Jack admits he's still a teacher at heart.
"I write every weekday but I always stop for 'morning playtime', lunch and 'afternoon playtime'," he chuckles. "I guess old habits really do die hard!"
Mister Teacher is published by Corgi books. For more information visit www.jacksheffield.com.