The weathering process takes time. Granted we’re not putting the object outside so that it can sit for a few years to naturally achieve sun/rain/wind damage and get all rusty and dirty. But the process isn’t instant and done in a single model session. For your typical object, the paint can chip and crack; it can get weather damages such as sun, wind, and rain; and it can also get dirty and rusty – just here, there are three layers of weathering that can happen. Applying the different techniques one on top of another can create some very dynamic weathered look to your object.