The present invention relates to a free-radically radiation-curable, solvent-free and printable precursor of a pressure-sensitive adhesive, the precursor comprising: (i) 30-75 wt. % of one or more mono(meth)acrylate functional oligomer compounds at least one of said oligomer compounds comprising at least one urethane bond, (ii) 0-15 wt % of one or more poly(meth)acrylate functional oligomer compounds, (iii) 5-45 wt. % of one or more monomer compounds comprising one ethylenically unsaturated group, (iv) 0-5 wt. % of one or more monomer compounds comprising two or more ethylenically unsaturated groups, and (v) an effective amount of one or more free radical photoinitiators, wherein the percentages which are percentages by weight with respect to the mass of the precursor, are selected so that the precursor has a dynamic viscosity at 20.degree. C. and at a shear rate of 100 s.sup.-1 of between 300 to 15,000 mPas.