Shared and demonstrated by Nicole Keller at the January 2016 Transit Traders Meeting
Sample by Nicole Keller
This technique can be used to create an interesting background for an ATC.
You will need watercolor paints, vinegar, baking soda, water, watercolor paper, a small container for mixing, and a dropper or pipette. This technique can be messy so work on waterproof surface. Also remember that the vinegar and baking soda can splash in your eyes.
1. Remove a watercolor paint disk of your color choice from the tray and break off about a quarter of the disk.
2. Dissolve the paint in a small amount of water. It is helpful to both stir the mixture and allow it to sit for a few minutes.
3. Add a pinch of baking soda and stir the three ingredients to combine. Nicole used a ratio of about 1/3 paint, 1/3 water, and 1/3 baking soda.
4. Using a paintbrush, paint the watercolor paper with the paint/water/baking soda mixture.
5. Allow the paint to soak into the paper for about 30 seconds to a minute, then use the dropper to add drops of vinegar to the painted paper. The acid in the vinegar will react with the base in the baking soda to create some interesting designs.
You can use a single color of paint.
Or use multiple colors to create a really interesting look.
After the background dries, embellish as normal to create a finished ATC!