Short lines are incised into the surface of this shaft at the top of each fillet between the flutes. These seem to have been guidelines incised into the surface of the stone to assist during the laying-out of the fluting. Guidelines of different types are seen on fluted columns from Aphrodisias and the Temple of Vespasian in Rome.
The flat surfaces on the entablature are flattened with the tooth chisel.
Notes
The Temple of Zeus at Euromos was built in the 2nd century AD on the site of an earlier temple. It is especially interesting because it was only part-finished, with some of its columns never fluted and others only roughly fluted.