[1] Interested in drawing since childhood, he attended Christ's College in Christchurch, and then the Ilam School of Fine Arts at the University of Canterbury from 1959 to 1962, where he was taught by Rudi Gopas, Russell Clark, and Bill Sutton.

Upon returning to New Zealand in 1970 he was employed as an entomological illustrator at Canterbury Museum, Christchurch, working alongside the painter Tony Fomison.

The scientist Sir Charles Fleming wrote, "Des Helmore's drawings supply the need for pictures of entire insects felt by many New Zealand amateurs and interdisciplinary students, to an artistic standard few can hope to emulate.

"[5] The entomologist Anthony Harris said, "Desmond Helmore's superb illustrations rank with the very best in the field – such as those of Arthur Smith, A. J. E. Terzi, and T.

"[10] Helmoreus, a genus of weevils, is named in his honour, "in recognition of his contribution to New Zealand entomology as a scientific illustrator".

[5] Reviewing his 2011 solo exhibition at Jane Sanders Art, for The New Zealand Herald, T.J. McNamara said:[15] He is an artist who cultivates enigma.

He takes ordinary places, landscapes and buildings and combines them into paintings that are truly strange yet curiously familiar... Helmore is an old-fashioned painter.

His draughtsmanship is impeccable as witnessed by his accurate scientific illustrations but there is no virtuoso flourish of drawing in his paintings: his forms are simple and clear.

Sometimes this makes the structure too open but generally the works are held together by strong compositions of angles, checks and balances...