A brand of modelling putty used by Games Workshop customers and people of a similar ilk. It comes as a strip that is yellow on one side and blue on the other. It is generally agreed that a 60-40 ratio of yellow to blue is practical.

Green stuff is usually used for small pieces of models, or filling in gaps. Occasionally an adept modeller will make something more interesting from it. It takes about an hour to dry, and a day to set hard.

There is an art to using green stuff, an art I have not mastered. It is the most infuriating bloody substance on the planet.

I am told it is similar to Milliput.