Printing ink

An inkjet ink having a viscosity of 30-100 mPa s at 40°C comprises (i) a radiation-curable oligomer, a passive thermoplastic resin, and/or a multifunctional monomer and (ii) 0.2-2 wt. % fumed silica, wherein if the ink comprises a passive thermoplastic resin, it also comprises a radiation-curable component. Typically, the ink comprises a non-wetting organic solvent and 0.5-1.5 wt.% fumed silica, especially hydrophilic silica. The radiation-curable component may be an oligomer or a multifunctional or other monomer, such as a difunctional (meth)acrylate. The oligomer may be an epoxy acrylate and the radiation-curable monomer may be hexanediol diacrylate. The ink may comprise 0.1-25 wt.% radiation-curable oligomer, 0.1-5 wt.% passive thermoplastic resin, 30-90 wt.% multifunctional monomer, and 1-20 wt.% photoinitiator. The ink preferably contains less than 5 wt.% water and less than 5 wt.% hyperdispersants. A method of inkjet printing the ink is also disclosed.