Chipping Paint
Works great to create Vintage Photos or to create leather textures.
Keywords: effect, photography, tutorial, free, photoshop, aging, noise, vintage, old, looking, Paint, Leather texture, Crackle.

1. Create a new layer.
2. >Filter>Render>Clouds using Black and White as your colors.

3. >Filter>Pixelate>Crystallize.

4. >Filter>Stylize>Find Edges

5. Change the Layer Mode to Multiply and reduce the Opacity.

Extra step: you could delete the white areas and add a bevel effect for an even better result.