DDO Painter Material Primer
Here's a breakdown of the material system in DDO Painter, explaining Basic Materials, Masking Patterns, Masking Presets and Smart Materials.
Substance Painter 2.3
The 2.3 version brings a full Photoshop export path from Substance Painter.
How to Paint Rocks in Photoshop
Marc Brunet shares a free video tutorial on how to paint rocks in Photoshop.