Materials And Set Up For This Watercolor Technique
First I drew a square in pencil, then found some Q-tips and 91% Isopropyl Alcohol. MATERIALS USED: Arches Cold Press 140lb watercolor paper, a 1½" wash brush, and the above mentioned items. COLORS USED: Dioxazine Purple, Ultramarine Blue, Cobalt Blue watercolor paint.
Laying the Field of Attack
I mixed a large amount of Dioxazine Purple and started blocking in a large wash on the paper.
The "Before" Picture
I continued painting in the rest of the loose wash with a Cobalt Blue and lay in some Ultramarine Blue in the upper left corner. You can prepare to drip alcohol onto your paint by dipping a Q-tip in alcohol.
The First Wave Is Never As Effective...
Here's where the magic of this watercolor technique begins. With the Q-tip saturated with alcohol, I proceeded to tap and drip alcohol directly into the washes. As the alcohol hit the wash it repels the paint, pushing it away while leaving a lighter tint of the wash exposed. Because the wash was so wet, I had to repeatedly drop alcohol onto the open areas to keep the flowing paint at bay. Alternatively, you can make sure your initial wash of paint has dried a little before proceeding to this step.
Getting Interesting Now
As the watercolor washes continued to dry, I tried some smaller splatters of alcohol throughout the area. During evaporation there passed a peak time for the effect to work best, although everything looks interesting so far. You will notice that each drop of alcohol produces a "fish eye" effect in the middle of most of the lighter areas where the color has slightly darkened.
Finished Example: Alcohol and Watercolor
I finished playing around and set the painting aside to dry. Alcohol and watercolor don't mix well. The result of their fight on the paper is strangely organic in nature and not achievable using any other technique. The "fish eyes" are a signature of this technique, so it's obvious to other painters what you are up to. Use it judiciously or with total abandon!