The oxidized copper is a difficult one to make it look good and realistic, it ofcourse also depends on your goal as there are a gazillion different looks oxidized copper can have. I would have tried to bring in more of the standard orannge'ish copper color in that material so that it shows through in some parts while the rest 70-80% of the material has this greenish oxidized look, if you don't mind me speaking freely now i think your current version feels too simple, like you slapped on a bitmap and then you were satisfied with that. I know you can do better Teabag.
About your bubinga wood material, only a couple of minor adjustments would i add to this one and it's by using a inverted copy of the wood colormap with saturation slider pulled down to -100 to keep the map greyscale i would have used that as a roughnessmap in a lightly weighted in secondary layer where i also dropped in a bumpmap with a low bumpvalue on it. Besides those things i think it looks good!
And please remember, these are only my own opinion and suggestions, it doesn't mean they're correct or what you should do. It might ruin your materials if you follow my suggestions, if you wanna do it, it's up to you hehe
/ Max
- By lebulb