Liquid masking fluid dries in several minutes. When you remove the masking fluid, the white area will perfectly maintain the white of the paper.
Additional tips when working with masking fluid:
* Use liquid masking fluid as a tool and not a crutch.
* Never use it with a good brush, period.
* Soap up your brush so that the fluid releases from the hair of the brush at clean-up.
* Clean your brush with soap and water.
* To remove the dry liquid mask make sure the painting is perfectly dry. Use a hard crepe rubber cement pick-up. This is a neat and easy way to clean up masking liquid. You can find the pickup for under $2.
* You can find liquid masking fluid at your art supply store. Try Cheap Joe's or Dick Blick's.