Newplast™ Plasticine is a non-drying, re-usable modelling material. It is still available in the traditional layered bar form familiar to many generations of children and adults. Newplast™ is sufficiently pliable to make a wide variety of models, but is firm enough to retain its shape indefinitely. Newplast™ is the material specified by most animators as being the only fit-for-purpose product of its type available.
Famously, Aardman Animations use Newplast Plasticine to animate some of their most famous characters.