Photoiniferter (PI)-RAFT polymerisation is a promising strategy to produce (meth)acrylic and styrenic polymers with a highly ‘living’ character, avoiding bimolecular termination common in conventional RAFT. A team has now studied the polymerisation of poly(poly(ethylene glycol) methyl ether methacrylate) (P(PEGMA)) under different conditions. Reading tip: Design of Experiments for CoatingsMaster the art of experimental design in coatings development with “Design of Experiments for Coatings“. Regression analyses revealed a strong correlation between the collision factor A and the extinction coefficients of the chain transfer agents (CTAs). A chain transfer constant (Ctr) above 1 indicated good control; Ctr decreased with increasing temperature.