/3/ - 3DCG

>>642158
>>642159
Both, my dude. The store looks old and run down, the paint shouldn't have 100% coverage. Use a grayscale noise texture (or hand paint something) where black = exposed wood like in >>642159 and white = painted like in >>642158. Then you can use a color ramp or adjust the contrast of the image to determine how much paint is worn off.

Pic related is a quick example I made of what you could do with such a method.