Games Workshop sells paint in spray-cans to its customers for them to apply a base coat to Game Workshop miniatures.
The miniatures are then over-painted by hand. The problem with this spray-can system is the hydrocarbon based propellant and paint systems that they contain. These produce inflammable green house gases: hazardous in transit, to users and the environment which are under increasingly stringent regulation, particularly in export markets. The can is also not reuseable.
Game Workshop's brief required a solution that avoids the hazardous propellant and paint system; a solution that avoids the need to discard the container at the end if a single filling.