Winsor & Newton Permanent Masking Medium is used to mask specific areas of paper, making them resistant to water. It can also be mixed with water colours and is ideal for isolating areas of fine detail. Unlike Art Masking Fluid, Permanent Masking Medium is not removable.
Permanent Masking Medium can be applied directly to white paper, to dried washes on the paper or mixed with water colours first. All water colour washes mixed with Permanent Masking Medium remain open and workable whilst the wash is still wet. Once dry, the area becomes isolated and cannot be fully penetrated by further washes. A hair dryer can be used to speed the drying. Brushes should be washed in warm water and soap before using other colours.
I've been meaning for some time to work with permanent masking in my art work so with these bargain priced items I'll soon be setting to work to experiment with this new format. I think it has to be good - it's W&N!!! Jay Farmer (UK) on 4 Oct 2015
Useful in sidestepping some compatibility problems. Stephen Warrington (Leeds, United Kingdom) on 26 Sep 2017
The permanent masking liquid is not as good as the removable one to isolate my painting/paper. I've even put the permanent masking liquid twice, but the result was not as clean as I expected. Note: I had waited until it was completely dried but not for an entire night. Eunike Nugroho (Sheffield, United Kingdom) on 21 Jun 2012