I love to color outside the lines! Either by doing a really messy artsy look or by keeping the images white and color the background instead. The easiest way to achieve this look when using wet media is to use making fluid on the images. Apply an even layer and let it dry fully before starting to work on the background. I used Sparkle Pens for this project. They are very pigmented so to achieve a softer look I spritzed the background with water and applied the sparkle pens on top for a soft wet on wet look. After drying I scribbled some Sparkle Pen on a glass surface and used a wet brush to pick it up and apply straight to the background. That added some sharper edges here and there without making the background to bold. I finished by spritzing some water drops on the background and dabbing them off with a dry paper towel. This lifts the color and creates little lighter circles like a bokeh effect.
Wait for your project to be totally dry before rubbing the masking fluid off using your finger or an adhesive eraser. Try to wipe off any color on top of the masking fluid before rubbing it off to prevent smudges on your white image.