In 1970 Stephenson returned to Chelsea Art School to become Director of the MA Course.

Returning to his studio in Elm Park Gardens, he became engaged by the images of the stacks of painting – layer upon layer, corners, edges appearing one behind the other; sometimes canvases supported by or displayed at angles to each other.  He made works on paper exploring juxtaposition, overlapping, subtle movements often through series in which collaged sections were moved into different positions concealing then revealing the marks beneath them.  In 1971 he painted two canvases, Band and Perpendicular, both explorations of extreme dimensions which could be hung horizontally or vertically.  In the same year he bought The Old School at Duddo in Northumberland, working there whenever possible until his death.  In 1972 he completed the ultimate statement about his method and technique, in symphonic style, with the Sandsend Series from Beyond the World’s End.  Four large canvases with eight supporting Understudies which, although now separated, were seen together at the De La Warr Pavilion and at the Baltic in Gateshead during 2006. The large works on paper, Border Series Easement I-VIII of 1976, bought by the Arts Council from the Retrospective Exhibition at the Hayward Gallery in 1977, are explosive and perhaps the first image of a rectangle rushing forward towards the spectator which has been seen in so many television graphics ever since. In 1977 Long Light was painted, a looking back to the more open romantic canvases of the sixties and anticipating a group of smaller canvases to be painted in the eighties.