A wind turbine blade and associated method of manufacture is described. The blade comprises an outer shell formed of first and second half shells joined together. A shear web is arranged inside the outer shell. The shear web has a web panel disposed between first and second longitudinally-extending mounting flanges. The shear web is bonded to inner surfaces of the respective half shells via a first adhesive bond line between the first mounting flange and the inner surface of the first half shell and a second adhesive bond line between the second mounting flange and the inner surface of the second half shell. One or more bond spacers are provided in the second bond line, and optionally in the first bond line. The bond spacers are compressed between a shear web mounting flange and an inner surface of a half shell and are plastically deformed. The method of making the shear web involves compressing and the one or bond spacers in the bond line(s) such that they undergo plastic deformation. This results in high quality bond lines.