Texture of a photoshop document that can be partially visible in a document through layers is a technique I decided to focus on to learn from a specialty magazine focusing on photoshop craft and practice. Within the texture tip reads that in order to create the texture, you must first create a new layer, press Shift-Delete, choose 50% Gray from the Use menu, and then click OK. Once you've whipped this up, you take it layer into the filer gallery to apply the texture and change the layers blend mode to Overlay or Soft Light. You put this on a separate layer so that if you become so inclined and decide to have the painting printed on canvas, you can turn off this little application.
Tip courtesy of Lisa Sage
Below are examples of images created using this photoshop technique::: they're free!!