Using Salt For Texture
The salt watercolor texture effect
Click image to enlarge.
As the washes dry the salt crystals suck up pigment gradually, creating a myriad of light star-like shapes. This is most noticeable in the sky areas and was less effective, and different, in the darker areas.
Experiment with various types of salt: table salt (iodized and non-iodized), sea salt, rock salt, kosher salt, etc. Larger grained salt will produce a larger, more pronounced starring effect.
I have no idea how salt affects the longevity of your art. Considering salt’s corrosive nature I would think over time it may interact with pigments and natural paper fibers in an unintended way.
For more on how to use this salt technique in real watercolor paintings, check out these examples: