Armstrong was born in Belfast but spent most of his working life outside the province of Ulster, painting with Gerard Dillon in London and with George Campbell in Dublin and Spain. Like so many Irish artists he was drawn to the West of Ireland where the raw vitality of the landscape from Connemara to Donegal provided the artist with Lego bricks enough to play with. The shapes can be built and re-built with infinite variety and Armstrong frequently interpreted the sense of structure very well. The massed shapes provide the bass notes and the eroded texture the melody. This involves a manipulatory skill in balancing the heavy brown tones with the scratched and modelled lines that rhythmically emerge from them in the form of individual rocks or walls.