Methods for producing optical effect layers comprising magnetic or magnetizable pigment particles

A method for producing an optical effect layer exhibiting one or more indicia on a substrate comprising the steps of:

• a) applying on a substrate surface a radiation curable coating composition comprising non-spherical magnetic or magnetizable pigment particles, said radiation curable coating composition being in a first, liquid state so as to form a coating layer;
• b) exposing the coating layer to a magnetic field of a magnetic-field generating device so as to orient at least a part of the magnetic or magnetisable pigment particles;
• c) subsequently to step b), applying a nonmagnetic top coating composition on top of the coating layer when the radiation curable coating composition of the coating layer is in a wet and unpolymerized state and the magnetic or magnetizable pigment particles are freely movable and rotatable, wherein said top coating composition is applied in the form of one or more indicia, wherein the top coating composition comprises one or more monomers and/or oligomers selected from radically curable compounds, cationically curable compounds and mixtures of radically and cationically curable compounds, wherein the cationically curable compounds are selected from the group consisting of vinyl ethers, propenyl ethers, cyclic ethers, lactones, and mixtures thereof, and the radically curable compounds are (meth)acrylates, and wherein applying the top coating composition on top of the coating layer alters an orientation of the magnetic or magnetisable particles under the top coating composition;
• and
• d) partially simultaneously with or subsequently to step c), at least partially curing the coating layer and the one or more indicia with a curing unit.