Watercolor and acrylic paint are somewhat translucent by nature, so it makes sense to preserve some areas of your paper or canvas so they stay white or light. Masking fluid is the best way to achieve that result.
Of course you can always use white gouache on top of watercolor, or paint with white acrylic on top of acrylic or watercolor, but you are loosing that transparency effect that is so unique to these media.
You might also be interested in:Watercolor and fluid acrylic: similarities and differences
You can paint with gouache on top of watercolor, like in the background of this portrait, but you are loosing some of the transparency of the medium. Although in portraits I like this effect of transparent and opaque passages.
Tip 1- Don’t shake the bottle but stir it
There are some chemicals composants in masking fluid, mostly latex and ammonia (preservative) that will agglomerate if you shake the bottle. So if you want to avoid big lumps in your bottle, gently stir the contents. If the fluid becomes too thick you can add a bit of water until you get to the right consistency.
Tip 2- Don’t Dry it with a hair dryer
It is tempting to use a hair dryer as masking fluid takes a long time to dry, but I don’t recommand it, especially on paper. The heat will make the latex bind to the paper and the masking fluid will be very difficult to take off.
The same thing can happen if the temperature in your studio is very high.
Tip 3- Masking fluid is great to preserve some details in a painting
Masking fluid works well for all the details that would take too much time to paint around like letters on a street sign or details in a flower.
Here I used masking fluid so I did not have to paint around the tiny bird legs.
Tip 4-Silicon brushes and dipping pens are the perfect tool to apply masking fluid
Masking fluid will stick to regular brushes and even if you cover them in soap before, it won’t be long before the brush feels like a stick. I find that the most convenient tool to apply masking fluid is a silicon brush, once the fluid had time to dry you can just peel it off the brush.
A silicon brush is the perfect tool to apply the fluid.
For bigger areas I also like to use a squeeze bottle to apply the masking fluid.
You can also apply masking fluid with a dipping pen.
Tip 5- It works great on canvas
Masking fluid is great for watercolor on paper but it works also really well with fluid acrylic on canvas. I use it all the time on my big canvas paintings to preserve some areas from being painted.
Here I want to preserve some light green fern leaves on a painting, I am using masking fluid to do so.
You can peel off dried fluid from a canvas the same way you would from paper.
Tip 6- Soften the edges
Masking tend to make very hard edges. If you want a more realistic look you might want to soften some of those edges.
On paper I would use a stiff brush and a bit of water to do so.
The edges left by the masking fluid are often very hard edges
You can easily soften them with a stiff brush and a bit of water.
On canvas you could paint over each masked area with a light white glaze or use a Mr Clean Magic eraser sponge and a bit of water to soften the edges.
A Mister Clean magic sponge works wonders to lift off acrylic from canvas.
Do you have some tips you would like to share about masking fluid?