I worked on the shading for these 3D models during my technical direction internship at Pixar Animation Studios. All the models were built in Maya, and I used Slim (a node-based shader tool) for shading. All the shading is procedural. I used fractals, noise, bump maps, displacements to generate variance and imperfections (scratches, slightly different hues, etc).
The great thing about procedural shading is speed (no need for painting by an artist), uniformity and lack of artifacting, ability to cover infinitely large areas with limited disk space required (as opposed to a giant image). I also loved the ability to use a bit of randomness to create very subtle variations in texture.
I think I could have done better with the metal on the edges of the wooden boxes - it definitely doesn't feel right to me. And I would have loved to experiment more with the velvet inside the violin case. I think I needed to play around with a gradient texture layer to remap the color based on the incidence angle to the camera (since velvet takes on a darker/lighter color depending on your angle of view.
