GOOD WEEKEND READING that should make those winter evening model-making sessions much more productive. It's a special online edition of a publication called 'The Weathering Magazine.'
There are useful instructions aplenty in the pages of The Weathering Magazine, and decent photography ensures that the results are shown in detail. There are lessons for scale model-makers who are new to the hobby, and plenty too for those with more experience.
Nice info given (below) for those who want that well-worn look. It's especially useful for World War II naval aircraft, exposed as they were to the worst of weathers and a corrosive environment.