
http://uk.games-workshop.com/thelordoft ... started/3/
To speed up the removal of the plastic sprues from the steel mould during the production process, the moulds are coated with a mould release agent. This oil leaves a greasy residue on the first few batches, so it is a good idea to wash your sprues with warm water and a mild hand soap to remove the agent. This cleaning will allow the primer to stick to the plastic better once you're ready to start painting.