|What you'll need|
- background material (I used watercolor paper, but any dry surface that will take paint will work.)
- liquid acrylic paints in two contrasting colors
- plastic wrap (I used blue wrap here to get better contrast in my photos)
Once your background material is dry, use the same very wet brush to apply a layer of the darker shade of paint (red). It's important that you make the layer very wet because you're going to want to move some of that color around in the next step.
Let the plastic wrap sit on top of the paint for a minute or so, then carefully peel it back. If you like the result you got, toss the plastic and let your background dry.
I use this technique often when I'm preparing papers to use in my visual journals. I hope you'll give it a try and let me know if this little tutorial was any help.