I have done all these textures in my spare time. Everything is 100% manually sculpted and assembled with ZBrush and some polishing in Ps.
This is a collection of ZBrush materials that I did in order to boost my sculpting skills and keep exploring the software. I really like to create materials using this tool. It takes time but the results are pretty and 100% handcrafted!
I presented all these assets using Marmoset Toolbag.