A method of applying a pressure sensitive adhesive to a substrate, which comprises the steps of: a) providing an uncrosslinked curable precursor of a pressure sensitive adhesive comprising: a (meth)acrylate copolymer component comprising: i. C 1 -C 32 (meth)acrylic acid ester monomer units; ii. ethylenically unsaturated monomer units having functional groups selected from the group consisting of acid, hydroxyl, acid anhydride, epoxide, amine, amide groups, and any combinations thereof; and iii. optionally, further ethylenically unsaturated monomer units which are copolymerizable with monomer units (i) and/or (ii); a thermal crosslinking system comprising a thermal crosslinker and optionally, a crosslinking accelerator; wherein the thermal crosslinker is selected from the group of compounds comprising functional groups selected from the group consisting of epoxide, oxazoline, oxetane, blocked or non-blocked isocyanates, and any combinations or mixtures thereof; at least one expandable microsphere; optionally, a tackifying system; and optionally, at least one pigment; b) subjecting the curable precursor of a pressure sensitive adhesive to a first heating step such that the curable precursor of a pressure sensitive adhesive is partially crosslinked; c) contacting the curable precursor of a pressure sensitive adhesive obtained in step b) to at least part of the surface of the substrate; d) subjecting the curable precursor of a pressure sensitive adhesive to a second heating step such that the curable precursor of a pressure sensitive adhesive is fully crosslinked; and e) optionally, allowing the polymeric foam layer to cool down on the substrate. a) providing an uncrosslinked curable precursor of a pressure sensitive adhesive comprising: a (meth)acrylate copolymer component comprising: i. C 1 -C 32 (meth)acrylic acid ester monomer units; ii. ethylenically unsaturated monomer units having functional groups selected from the group consisting of acid, hydroxyl, acid anhydride, epoxide, amine, amide groups, and any combinations thereof; and iii. optionally, further ethylenically unsaturated monomer units which are copolymerizable with monomer units (i) and/or (ii); a thermal crosslinking system comprising a thermal crosslinker and optionally, a crosslinking accelerator; wherein the thermal crosslinker is selected from the group of compounds comprising functional groups selected from the group consisting of epoxide, oxazoline, oxetane, blocked or non-blocked isocyanates, and any combinations or mixtures thereof; at least one expandable microsphere; optionally, a tackifying system; and optionally, at least one pigment; a (meth)acrylate copolymer component comprising: i. C 1 -C 32 (meth)acrylic acid ester monomer units; ii. ethylenically unsaturated monomer units having functional groups selected from the group consisting of acid, hydroxyl, acid anhydride, epoxide, amine, amide groups, and any combinations thereof; and iii. optionally, further ethylenically unsaturated monomer units which are copolymerizable with monomer units (i) and/or (ii); i. C 1 -C 32 (meth)acrylic acid ester monomer units; ii. ethylenically unsaturated monomer units having functional groups selected from the group consisting of acid, hydroxyl, acid anhydride, epoxide, amine, amide groups, and any combinations thereof; and iii. optionally, further ethylenically unsaturated monomer units which are copolymerizable with monomer units (i) and/or (ii); a thermal crosslinking system comprising a thermal crosslinker and optionally, a crosslinking accelerator; wherein the thermal crosslinker is selected from the group of compounds comprising functional groups selected from the group consisting of epoxide, oxazoline, oxetane, blocked or non-blocked isocyanates, and any combinations or mixtures thereof; at least one expandable microsphere; optionally, a tackifying system; and optionally, at least one pigment; b) subjecting the curable precursor of a pressure sensitive adhesive to a first heating step such that the curable precursor of a pressure sensitive adhesive is partially crosslinked; c) contacting the curable precursor of a pressure sensitive adhesive obtained in step b) to at least part of the surface of the substrate; d) subjecting the curable precursor of a pressure sensitive adhesive to a second heating step such that the curable precursor of a pressure sensitive adhesive is fully crosslinked; and e) optionally, allowing the polymeric foam layer to cool down on the substrate.