National Model Railroad Association’s Master Model Railroader Gerry Leone demonstrates the use of a paint mixer in this video. Modeling experts like Leone say that shaking a jar of paint is not the best way to disperse the pigment. This method of mixing disperses the pigments unevenly and gets paint on the lid of the jar which can harden and make the jar difficult to open later on.
The best way to disperse the pigment evenly and thoroughly is with a paint mixer. Badger Airbrush Co makes a hand held battery operated paint mixer with a small mixing head that turns very quickly. It runs on two AA batteries and costs between ten and fifteen dollars at most hobby stores or by mail order. One downside to a paint mixer is that if it is left on just a bit too long as it is being pulled out of the paint, it can splatter. Leone solves this problem by using a plastic juice bottle with the bottom cut off to create a sort of funnel that fits over the neck of the paint jar while mixing, catching all the splatters.
Leone demonstrates on paint that has settled and been left unmixed how in just ten to thirty seconds with the paint mixer the pigment is thoroughly dispersed. For more tips and techniques like painting backdrops for your layout, visit the Model Railroad Academy website.