One of the frustrating things about painting with watercolors is that once you paint a dark color you can’t paint a lighter one on top.
Well, what if you could preserve the lighter areas before you add the dark hues?
That is why in this post you will learn all about how to use masking fluid for your watercolor paintings so you can do just that!
Let’s get started…
What is Masking fluid?
In watercolor painting, masking fluid is liquid latex that can be used to preserve the lighter values of a painting.
A good example would be when you’re painting snowcapped mountains or water reflections; it helps preserve the highlights.
How to use masking fluid
To use masking fluid, simply apply it to the areas you wish to preserve. Next, allow it to dry, then paint over it like normal. After the paint has dried, gently rub the dried fluid with your hands to remove it.
Here’s the process in detail:
1. Planning your painting
Before you begin painting, you first need to know what areas you wish to preserve. Creating a value sketch can make a huge difference with this step. Draw the general outline of your painting using a pencil.
Note down where the lightest areas will be; that’s where you’ll want to apply the masking fluid.
2. How to apply it
For this step, you’ll need a brush. Never use a good-quality brush with masking fluid because it will get ruined!
If you don’t have a spare brush, you can use the end of a brush handle or a toothpick.
Start by pouring a small amount of masking fluid in a separate bowl or small dish. Masking fluid dries very fast after it’s exposed to air, so close the bottle immediately after you’re done.
That way it will last for months.
If the masking fluid is too thick, you can pour a small amount into a bowl and mix in very little water to make it easier to apply.
With your brush, apply the masking fluid on the areas you marked in your sketch.
Rinse your brush with water; however, don’t use the same water to paint with.
Before you begin painting, make sure the masking fluid has completely dried. You’ll be able to tell it’s dry once it’s rubbery.
After it has dried, you can paint over it and finish your painting like normal.
3. Make sure the masking fluid is dry
You can tell if masking fluid is dry just by looking at it. When it’s dry, you’ll see it isn’t reflective because of its rubber-like texture. If you notice an odor, then that means it’s still wet.
If you can’t tell by looking, use your finger or a toothpick and gently poke it, if it’s wet, it’ll stick to the toothpick. However, if it’s dry it won’t stick and will feel rubbery.
Patience is key here; you don’t want to start painting while it’s still wet, otherwise it’ll dilute the fluid and ruin your painting.
4. How to remove the masking fluid
To remove the masking fluid, the paper must be completely dry. This is because if the paper is still wet, you could end up ripping it.
You can remove it by hand or using different tools such as a rubber cement eraser.
Most artists just use their hands by gently rubbing them on the paper to remove it. Remember not to use too much pressure or go too quickly, as this could cause the paper to rip.
NOTE: Never leave masking fluid longer than two days; otherwise, it can become very hard and rip the paper when removing it. If you plan on finishing your work another day, it’s best to remove it and then reapply it the next time you work on it.
4. Soften and blend
Once you remove the fluid, you may notice sharp edges; for this reason, you may want to soften some of them. You can do this by re-wetting the edges with a damp brush and lifting the pigment or blending it.
How to Store Masking Fluid – Best Practices
Masking fluid can dry up very quickly. To prevent it from drying up too quickly, try these tips:
- Never shake the bottle; stir it instead if you have to. Only if you have to.
- Avoid leaving the bottle open for longer than 2 to 3 minutes when you use it. Try pouring a little in a separate container to apply, then close the bottle immediately.
- Add some plastic wrap on the bottle before closing the lid; this will ensure it’s airtight.
- Store it upside down, this helps it stay fluid longer
- Never contaminate the masking fluid with other materials
- Don’t keep it stored near heat or direct sunlight
How to use masking fluid wet on wet
Another way to create softer edges is by applying the masking fluid on wet paper. Here’s how:
- Wet the paper with clean water, you don’t want to dilute the fluid too much so don’t over-wet the paper.
- Dab the masking fluid into the area you want to preserve and allow it to dry.
- Finish the rest of the painting and wait for it to dry
- Remove the fluid and finish up the painting
This technique can be very handy for negative painting. The images below shows each step:
Different types of fluid
Masking fluid comes in different colors such as blue. This is to help the artist see where they’ve applied it in their painting. You can also purchase it in different forms: bottled and marker pens.
While marker pens are more convenient for quick work and your brushes stay safe, bottled versions allow for more flexibility. Marker pens are also great for beginners, while bottled versions are preferred more by experienced artists
At the end of the day, it all comes down to personal preference.
Masking Fluid Techniques to Try
Below are a few techniques you can practice with or use in your watercolor paintings.
Painting water
Being able to preserve the reflective areas when painting lakes, rivers, and waterfalls makes everything so much easier. To use this technique, apply the fluid onto the paper where the reflections are. Paint over it starting with a light blue and then dropping in some dark blue.
The images below show a rough example of using this technique:
Splattering
You can use a toothbrush or paintbrush to splatter small dots across the sky of your painting to create galaxy paintings or a night sky. Here’s how to splatter:
Layering
You can mask the areas of your painting after adding the first layer. Simply wait for it to dry then apply the fluid like normal.
Using frisket film as an alternative
Frisket film is an adhesive used to temporarily mask areas of your painting. It works as a great masking fluid alternative too!
A few things you should consider when using frisket film as an alternative:
- Buy extra tack film and not the all-purpose low tack. The extra tack works better with watercolor and prevents the water from seeping underneath.
- Don’t press too hard when applying it
- It works better with cotton paper. Cheaper papers have been known to rip.
Extra Tips and FAQ
What is the average drying time of masking fluid?
It doesn’t take very long for masking fluid to dry, if you live in an area with less humidity it’ll dry faster, between 5-10 minutes. If you live in a warmer, humid climate, it’ll take between 15-20 minutes to dry.
I live in a dry climate with less humidity, so I did a test to see how long it would take for the masking fluid to dry.
A thin layer of masking fluid took about 2 minutes to dry, while the thicker areas took about 4.5 to 5 minutes.
Keep in mind that this was fresh masking fluid bottle that had just been opened.
How long does it take for a masking fluid bottle to harden?
After a certain amount of time, your masking fluid bottle will dry up. If you expose the masking fluid to air it will dry faster. My first bottle dried up within 6 months because I would leave it open for at least 5 to 10 minutes as I applied it.
What happens if you leave masking fluid on the paper for too long?
Leaving masking fluid on the paper for a few days should be fine if you have a big project. However, leaving it on your paper for too long will cause it to harden and stick to the paper.
If you’re going to be working on your piece for weeks, then it is better to remove and re-apply it. The last thing you want is for all your hard work to rip!
Always change the water
Once you’ve applied the fluid and cleaned your brush, make sure to clean out your jar and fill it with clean water. You don’t want to use the same water to create your painting.
Can you use masking fluid on painted areas?
You can use masking fluid on already painted layers, provided that the previous layer has dried and that you don’t leave it for too long. If you plan on not working on your painting for days on end, remove then reapply it.
Is it okay to use a hair dryer?
Using a hair dryer or any heat tool may cause the dried masking fluid to stick to the paper and become very difficult to remove.
Can you mix masking fluid with water?
You can mix the masking fluid with a few drops of water to make it easier to spread and apply. However, adding too much water will make your painting chalky and the masking fluid will no longer be water-resistant.
Can you reuse masking fluid?
Once dried, the masking fluid can not be reused, it won’t stick to your paper or preserve areas of your painting. It will turn into a rubbery texture and you’re better off re applying more.
Are there alternatives to masking fluid?
There are some alternatives you can try, including wax resist, oil pastel, masking tape, lifting, and blotting. Learn more about the other options in this article: 8 Excellent alternatives to Masking Fluid
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