John Armstrong took art lessons while serving in the UK Army in the Far East. Back in civil life, he went to art school in Middlebrough's Constantine College, where he graduated in Intermediate Arts and Crafts. He started as a commercial artist for a Newcastle ad agency while also doing book illustrations. He eventually also took on drawing comic strips and has mainly worked for the UK girls' titles during the 1970s, 1980s and 1990s. After a ballet story published in Girl's Crystal, he drew 'Cherry and the Children' for five years in School Friend.
Armstrong is best known for his gymnastics strip 'Bella', that ran in Tammy. By 1978 he was drawing 'Moonchild', a girls' story with horror elements, for Fleetway's Misty. In the 1980s he drew a comic based on the children's school drama 'Grange Hill' for Beeb and then began an association with the girls' titles of DC Thomson, drawing 'The Secret Gymnast' and horse stories for Bunty, among other things.
Sue on Stilts (Girls Crystal annual 1962)