How to weather a model.

[Phil]

Layers are your best friend. Well, my best friend anyway. The only tricky part for me is layer management. Trying to draw on a top layer when I really want a bottom layer etc. Check which layer is selected before each step.

[zubie]

Pretty much what everyone else said...particularly about the layers.

I would suggest playing around with the various tools, particularly if you haven't used "effects" yet, although you may be surprise how useful a relatively small number of tools or effects can be (many can go overboard).

With respect to the layers, take advantage of variable transparency as some effects that may appear too strong can be toned down to be just right without wasting time in choosing variable brushes and pressures.

Also make a note that not all weathering is the same, which is part of why layering is important. For instance there are weathering effects that are due to rain while parked, so effectively downward, but then you have airflow weathering which is effectively along the lines of the airflow, or maybe sun fade which affects the more exposed areas and rather than darkening the subject can create a mottled bleached effect.

The same basic ideas behind weathering to a physical model can apply to the digital one: Undercoats can be a base layer color or monochromatic duplicate layer, the effect of staining and blowing can be simulated with digital spray painting followed by a motion blur, adding noise or using a stippled brush to either paint or erase (remember erasing can be useful to reveal lower layers) can duplicate similar effects generated by rough brushes or scratching, and so on. The nice thing about digital, is that if you go through a lot of trouble to create the perfect oil or rust streak, you can then copy it and scale and paste in some other appropriate spot.

Oh, give meaningful names to those layers...I keep forgetting and then accidentally merging or deleting the wrong ones

[codex34]

I never knew about the wind filter, 15 years of doing it the hard way - lol.

You can add some types of weathering with a simple texture on a different layer using multiply or hard light.
You can get the textures off google mages, 'dirt texture', 'weathering texture', concrete texture', 'grunge texture', 'noise texture' etc..
Tip - turn the colour down on your screen when searching, shows the images as 'effects' better.
My favourite weathering texture is snow!!!!