Through living in Hammersmith he met Edward Johnston, Eric Gill and Frank Brangwyn. It was here he set up the Hampshire House Workshops, an organisation set up after the Toynbee Hall model and which aimed to improve the prospects of working men. After Gill and Johnston moved to Ditchling, Pepler wrote to Johnston:
Can you think of any work I can do in Ditchling? We want an excuse to follow the prophet (you) into the wilderness.
He moved to Ditchling in 1913 and immediately set to work as a printer, establishing St Dominic’s Press using a 100-year-old Stanhope Press (now resident in the museum). At the same time he converted to Roman Catholicism and changed his name to Hilary. The Press produced sacred and secular works, using illustrations by Gill, Hagreen, David Jones and Pepler himself.
He was a founder member of the Guild but differed with Gill on the approach to it – their friendship suffered a blow after Gill resigned and left for Wales in 1924. Their relationship was never mended, despite Pepler’s son David marrying Gill’s daughter Betty (a marriage which Gill did not favour). After being expelled from the Guild in 1934 he moved the Press from the Common to the village and renamed it Ditchling Press in 1937.