Weathering, especially streaking and pigment application, requires very soft brushes to control the effect and not remove it altogether.
With these double-headed brushes, which come in two different models, you can achieve professional-looking results in no time.

We have to prepare each shipment individually as they are ordered, so allow it 3-4 weeks to arrive in the USA/Canada (to be safe) and 3-6 weeks rest of the world, though they are usually delivered much faster.