His parents, Olive and Aubrey, and an older sister, Janet, lived in the village of Gorefield, near Wisbech "Capital of the Fens" of East Anglia.
His artistic skills and enthusiasm were encouraged, not by the school, but by Bill Wright, who had a signwriting business, and an Art Materials and Photography shop in Wisbech.
Ray was proficient in drawing, watercolour and oil painting at the age of 15.
Unaware of such a thing as an Art School, Ray applied for a 2 Year Teacher Training Course at Trent Park Teacher Training College, Barnet.
He joined the Intelligence Section, served in Germany and on active service in Cyprus.
Reached the rank of Corporal - unusual for national service personnel.
Whilst teaching, he continued his own personal paintings and exhibited widely in the North of England during the sixties and seventies.
His first illustrations were cartoon drawings, about teaching, which were regularly published in the Times Educational Supplement and Teacher's World.
He became interested in children's book illustration, and after overcoming a series of rejections, Yorkshire Television used his artwork in the national T.V.
His illustrations for traditional and new stories, including some of his own, were shown on the programmes for four years.
One of its successes was time charts which took the form of a 4-part frieze showing the history of an industry or institution.
Ray illustrated history Time Charts for The Inland Revenue, The Banking Information Service, The Royal Mint, Pilkington Glass (history of windows), Thames Water and The Atomic Energy Authority.
He also designed and illustrated fourteen A1 and A2 posters for similar institutions, including The Royal Society of Arts.
Postman Pat is a TV character created by Ivor Wood and writer John Cunliffe.
In 1989 Ray started his first series of 12 Postman Pat picture books called "Tales from Greendale", published by Andre Deutsch Children's Books and Scholastic.
For Egmont Publishing he did a number of Postman Pat board books for younger children drawn in a simple heavy black line style and computer coloured.
From 1982 to 1988, Mutimer wrote, designed and illustrated pages of craft "how to make" activities for children.
The longest running was "Make with Mum" in Pepper Street, published by DC Thomson.
For four years, he drew another TV character created by Ivor Wood, Charlie Chalk.
Towards the end of the comic's life he also drew Postman Pat on the covers and inside.
He gave the fortnightly "Play and Learn Postman Pat" spin off striking fully painted covers as well as interior picture strips.
Working for Marvel UK from 1992 to 1994, on Rupert and friends and Rupert Learn and Play – weekly children's picture strip magazines, Ray illustrated four page picture stories and activity pages called Bingo's Workshop.