A polymeric material has a repeat unit of formula —O-Ph-O-Ph-CO-Ph- I and a repeat unit of formula —O-Ph-Ph-O-Ph-CO-Ph- II wherein Ph represents a phenylene moiety; wherein the repeat units I and II are in the relative molar properties I:II of from 65:35 to 95:5; wherein log10 (X %)>1.50−0.26 MV; wherein X % refers to the % crystallinity measured as described in Example 31 and MV refers to the melt viscosity measured as described in Example 30. A process for making the polymeric material comprises polycondensing a mixture of at least one dihydroxybenzene compound and at least one dihydroxybiphenyl compound in the molar proportions 65:35 to 95:5 with at least one dihalobenzophenone in the presence of sodium carbonate and potassium carbonate wherein: (i) the mole % of said potassium carbonate is at least 2.5 and/or (ii) the following relationship applies (formula III).