A pressure-sensitive adhesive comprising at least 60 wt % of a polymer blend, where the polymer blend consists of a first polymer component A, a second polymer component B, and optionally one or more further polymer components (C, D, . . . ), where the first polymer component A is present at not less than x wt % in the polymer blend, where 90≤x≤99, and where the second polymer component B and any further polymer components C, D, . . . present are present in total at y wt % in the polymer blend, where y=100−x, where each polymer component (A, B, C, . . . ) derives to an extent of at least 60 wt % from (meth)acrylic monomers, wherein none of the polymer components (A, B, C, . . . ) is homogeneously miscible at room temperature with any of the other polymer components (A, B, C, . . . ), and so a multi-phase system is present.