A process for the preparation of a composite article by curing a composite comprising: - layers of structural fibers and - a composition comprising: a) an epoxy thermosetting resin; b) a curing agent; and c) at least two types of toughening particles wherein a first type of toughening particles is insoluble in said epoxy thermosetting resin upon curing of said epoxy thermosetting resin; and - wherein a second type of toughening particles is partially soluble or swellable in said epoxy thermosetting resin upon curing of said epoxy thermosetting resin, - wherein said first type of toughening particles and said second type of toughening particles are in an interleaf layer between the layers of structural fibers, - wherein the mass fraction of the first type of toughening particles is from 1 % to 15 %, based on the mass of the composition, and the mass fraction of the second type of toughening particles is from 1 % to 15 %, based on the mass of the composition, and - wherein the first type of toughening particles are polyphthalamide particles, wherein - a particle is considered swellable if its particle diameter or particle volume, compared to that of the original particle sample, changes by more than 5 % as measured on a hot stage microscope, with a loading of particles of 10 wt% of the resin matrix containing no curative or catalyst, upon heating to the desired cure temperature, and - a particle is considered insoluble if its particle diameter or particle volume, compared to that of the original particle sample, changes by less than 5 % as measured on a hot stage microscope, with a loading of particles of 10 wt% of the resin matrix containing no curative or catalyst, upon heating to the desired cure temperature, - wherein said epoxy thermosetting resin is curable within the temperature range of 140°C and 200°C. - layers of structural fibers and - a composition comprising: a) an epoxy thermosetting resin; b) a curing agent; and c) at least two types of toughening particles wherein a first type of toughening particles is insoluble in said epoxy thermosetting resin upon curing of said epoxy thermosetting resin; and a) an epoxy thermosetting resin; b) a curing agent; and c) at least two types of toughening particles wherein a first type of toughening particles is insoluble in said epoxy thermosetting resin upon curing of said epoxy thermosetting resin; and - wherein a second type of toughening particles is partially soluble or swellable in said epoxy thermosetting resin upon curing of said epoxy thermosetting resin, - wherein said first type of toughening particles and said second type of toughening particles are in an interleaf layer between the layers of structural fibers, - wherein the mass fraction of the first type of toughening particles is from 1 % to 15 %, based on the mass of the composition, and the mass fraction of the second type of toughening particles is from 1 % to 15 %, based on the mass of the composition, and - wherein the first type of toughening particles are polyphthalamide particles, - a particle is considered swellable if its particle diameter or particle volume, compared to that of the original particle sample, changes by more than 5 % as measured on a hot stage microscope, with a loading of particles of 10 wt% of the resin matrix containing no curative or catalyst, upon heating to the desired cure temperature, and - a particle is considered insoluble if its particle diameter or particle volume, compared to that of the original particle sample, changes by less than 5 % as measured on a hot stage microscope, with a loading of particles of 10 wt% of the resin matrix containing no curative or catalyst, upon heating to the desired cure temperature, - wherein said epoxy thermosetting resin is curable within the temperature range of 140°C and 200°C.