Ok here’s my take on brass: You have a highly specular, maleable material with a fairly high oxidation capacity. With that in mind (in Photoshop) for your base colour, select a brass colour (duh) and throw in a darkened black monochrome noise (muck around with some filters overthat) on a separate layer.
On a new layer, start painting scratches (using an darken layer filter), and underneath that create a ‘shadow crease’ for these scratches. Do similar for dents - you’ll notice that with it’s rather high maleability, brass dents easily so go mental with different brushes. try to emulate where it’s hit flat or cornered surfaces, and they tend to be the more pronounced. I tend to do the scratches first as the dents will distort these scratches, but scatches will occur after denting (more or less) so add a few more.
Once that’s done, on a new layer (lighten filter) create some highlights off these dents and scratches. These will vary in width from the depth of your dent/scratch. This goes above the dents layer, using a lighten layer filter. You don’t neccesarily need to use white, I tend to find that using a hue brighter than the brass hue is more effective.
Because (I’m assuming) you’re dealing with a man-made object, it would be machined to some extent, so maybe some lathe lines or something of the ilk. These should be really subtle and use a darken layer filter with a dropped opacity. Oh yeah, put it underneath the dents layer.
Make another noise map (dark green), and use a layer filter over the top to emulate oxidation (I’d suggest which filter, but I don’t have PS on this comp [at work], Overlay filter should work I think). Apply a layer mask to make it look like its embedded into some of the scratches etc.
Finally, on a new layer, start painting in rub marks. These are bits where the metal has been brushed against something - whether once or continually depends in the local environment of the object. Once you’ve pinted these in, do a layer select and go through your alteration layers and start erasing pits appropriately, using a low opacity brush.
Hide your working rub painting and save out. Voila!
Dang, gotta get back to work, HTH Mælefic out 