Masking in watercolor painting is a technique that allows artists to protect specific areas of the paper, preserving the white of the surface or previous layers of color.
Whether using masking fluid, masking tape, or liquid frisket, the goal is simple: block out parts of the painting from washes and pigment, ensuring sharp edges and clean highlights.
Knowing how to effectively apply and remove these materials is essential for creating depth and detail in your work.
This article will walk you through what is masking technique in watercolor painting, why it’s essential for controlling light and preserving details, and how to use various tools like masking fluid, frisket pens, and stencils to achieve professional results.
By the end, you’ll understand how to integrate these techniques into your watercolor practice and avoid common pitfalls that can damage your artwork.
Types of Watercolor Masking Techniques

Masking Fluid
Masking fluid is probably the most common tool when it comes to preserving white areas or protecting intricate details in watercolor painting.
It’s a latex-based liquid that can be applied with a brush, nib, or masking pen to areas you want to remain unpainted.
Once dry, it forms a protective barrier that resists watercolor paint, making it easier to work on the rest of your painting without worrying about accidentally covering parts you want to keep clean.
Choosing the right masking fluid can make a difference in your work. Artist-grade fluids like Winsor & Newton or Pebeo offer smoother application and easier removal.
Avoid cheap alternatives—they tend to tear the paper when removed.
Timing is crucial with masking fluid; always let it dry thoroughly before painting over it, and make sure your painted areas are completely dry before removing it to avoid damaging the paper.
Brushes for masking are typically old or inexpensive ones because masking fluid can ruin the bristles.
Alternatively, some artists use specific masking tools like ruling pens or rubber-tipped applicators.
Masking Tape
Masking tape is another essential tool, particularly for creating crisp edges in watercolor. You can use it to section off straight lines, borders, or geometric patterns.
The tape protects the paper beneath from any watercolor washes you apply over it.
Painter’s tape or artist’s tape tends to be the best for this job as they are designed to be low-tack and won’t tear the paper when removed.
To avoid seepage, make sure the edges of the tape are pressed down firmly before applying your wash.
A good tip: stretch your watercolor paper before taping to prevent buckling, which can allow paint to slip under the tape.
Liquid Frisket
Similar to masking fluid but often more refined, liquid frisket can be used for delicate lines and intricate areas.
difference lies in the consistency—it tends to be thinner and sometimes offers a more controlled application, especially when used with a frisket pen or a fine applicator.
Unlike masking tape, liquid frisket offers flexibility for detailed sections and curves. Be careful during removal, though. Like masking fluid, removing it too soon or too late can risk tearing the paper.
Masking Stencils
Masking stencils are useful for specific patterns or shapes you want to block out in your painting.
These stencils can be made from plastic or paper, and you apply paint around them to leave the masked area untouched. This technique is particularly useful for repetitive designs or controlled negative space painting.
The downside here is that stencils can sometimes shift if not held firmly in place, so artists often use low-tack spray adhesive to keep them in place.
Masking Pens
Masking pens are designed for precision. These pens are filled with masking fluid and allow you to draw directly onto the paper with detailed lines or shapes.
They’re perfect for adding highlights, tiny details, or intricate patterns, offering much more control than using a brush.
However, one pitfall of masking pens is that they can clog easily if not cleaned properly. And since the lines they create tend to be quite thin, you need to make sure they’re fully dry before painting over them to avoid smudging.
Pitfalls to Avoid
- Damaging the paper: One of the biggest risks when using masking techniques, especially with fluid or frisket, is damaging the paper. Always test on a scrap piece first.
- Leaving masking fluid on too long: If you leave masking fluid on the paper for extended periods, it becomes harder to remove and increases the risk of tearing.
- Inconsistent masking: Uneven application of masking fluid or poorly pressed masking tape can lead to inconsistent edges or paint seeping underneath.
Techniques for Applying Masking Fluid
Choosing the Right Brush
When applying masking fluid, you have to start with the right tool. The thing is, masking fluid can ruin a good brush.
So, don’t grab your favorite sable brush for this. Instead, go for an old or inexpensive brush.
Synthetic bristles work best here because they can handle the rough treatment. You can also use silicone-tipped applicators or frisket pens for even more control, especially when working on small details.
Another option is to coat your brush with a bit of soap before dipping it into the masking fluid.
This prevents the fluid from clumping up in the bristles and makes cleanup easier. Just don’t forget to wash the brush immediately after use.
Controlling the Flow
The thickness of masking fluid is key to how it applies. If the fluid is too thick, it’s going to clump and make the application uneven.
Sometimes, adding a few drops of water to thin it out is necessary, but not too much, or you’ll lose the resist properties.
For broad areas, use a larger brush, and for tiny, delicate areas, a masking pen or ruling pen works best.
A frisket pen will allow for fine lines, whereas a brush can cover larger sections, giving you the option to work at different scales. Watercolor resist techniques often depend on this balance of fluid control.
Applying Evenly
An even coat of masking fluid ensures that the protected areas stay crisp and free of watercolor paint.
Too thin, and the watercolor will bleed through. Too thick, and it might tear your paper when you remove it. The key is consistency, and that comes with practice.
Use slow, deliberate strokes. Don’t rush it. If you’re working on intricate areas, make sure you allow the masking fluid to dry completely before applying your paint.
It doesn’t take long, but trying to paint over wet masking fluid will just create a mess. And never use heat to dry masking fluid faster—it can cause it to bond too strongly to the paper.
Timing Matters
Don’t leave masking fluid on your paper too long. Sure, it’s tempting to mask an area, finish the rest of your painting over several days, and then come back.
But if the fluid sits on the paper too long, it can stain or become almost impossible to remove.
The optimal window is to keep it on the paper only as long as necessary to finish your work. Removing it as soon as your paint is dry will prevent unnecessary damage to your watercolor paper.
Removing the Masking Fluid
Once you’re done painting, and everything has dried, it’s time to remove the masking fluid. This can be tricky.
You want to make sure you don’t tear the paper. Using your fingers is generally the safest way, as they’re soft enough to avoid scraping the surface.
Some people use a rubber cement eraser or a soft cloth. If the masking fluid is too stubborn, it probably means it’s been left on the paper too long.
Avoid scratching or rubbing too hard—this is especially crucial if you’re working with more textured watercolor paper like Arches or Fabriano.
The last thing you want after spending hours on your artwork is to peel away parts of your paper with it.
Pitfalls to Avoid
- Overloading the brush: Too much fluid on the brush will result in clumps and uneven application.
- Skipping the soap: Forgetting to coat your brush with soap can make cleaning nearly impossible.
- Rushing the drying process: Applying paint before the fluid is fully dry causes smudging.
Best Practices for Masking Fluid Application

Use the Right Tools
It starts with the right tools. Old, cheap brushes are your best friend here. Masking fluid will destroy fine brushes, so leave the good ones for painting.
Synthetic brushes work well because they’re easier to clean. You can also use masking pens for detailed work. If you’re working on a larger area, a frisket pen or a rubber-tipped applicator is an option.
Coating the brush with soap before dipping it into the fluid helps too. This makes sure the fluid doesn’t cling too tightly to the bristles, and cleanup afterward becomes a lot simpler.
Timing Is Key
Masking fluid needs time to dry. Not a lot, but you can’t rush this part. Apply it in thin layers and wait for it to dry completely before you even think about painting over it. Use a thin, even coat to avoid tearing the paper later.
Heat guns or hair dryers? Forget it. Don’t speed up the process with heat.
That will just lead to the masking fluid bonding too tightly to the paper, which makes it almost impossible to remove without damaging the surface.
Avoid Leaving It on Too Long
Once you’re done with the painting, take the masking fluid off sooner rather than later. Leaving it on for days or even weeks can lead to issues.
The longer it sits, the more likely it will start to stain the watercolor paper or become too hard to remove.
Frisket pens and masking fluid are designed for temporary use, so keep them that way. The optimal window? Remove it as soon as the paint is dry. No longer.
Apply Evenly
You don’t want any blobs or clumps of masking fluid, especially when you’re trying to preserve small details.
If you’re going for larger areas, sure, it’s easier to spread out with a bigger brush. But when you’re working with fine details, a masking pen is the way to go. It allows for better control and ensures precision.
If the fluid is too thick, you might need to add a tiny bit of water to thin it. Don’t overdo it, or you’ll lose its resist properties. The goal is even coverage.
Avoid These Common Mistakes
- Skipping the soap step: If you forget to coat the brush with soap, good luck cleaning that masking fluid off. It will cling to your bristles and likely ruin the brush.
- Applying the fluid unevenly: This causes blotches, and you’ll end up with inconsistent masking, which can let paint seep through in spots you wanted to keep white.
- Leaving the fluid on too long: Let it sit for too long, and you risk damaging the paper or having it fuse with the watercolor wash. Stubborn removal equals torn paper.
Combining Masking Techniques in Watercolor Art
Layering Masking Fluid and Tape
Combining masking fluid with masking tape is an efficient way to create varied effects in watercolor.
The tape provides crisp, geometric edges, while masking fluid allows for more organic, detailed shapes. This combo works well when you’re looking to balance hard edges with softer, more intricate areas.
Apply the tape first to protect large areas or create sharp borders. Once the tape is securely down, you can use the masking fluid to block out smaller sections within those borders.
After the fluid dries, you can paint over the entire area without worrying about smudging into the masked-off zones.
Incorporating Stencils with Masking Fluid
For even more control over patterns or specific shapes, masking stencils can be used alongside masking fluid.
Stencils work best for repetitive designs, such as textures or backgrounds, while masking fluid can be used to protect the highlights or intricate focal points.
After placing the stencil on the paper, apply liquid frisket or masking fluid to preserve the pattern.
This method allows you to build layers and maintain both negative and positive space. Make sure to remove the stencil before the masking fluid dries to prevent any tearing or smearing.
Using Multiple Layers of Masking Fluid
If you’re aiming for more depth in your painting, multiple layers of masking fluid can help achieve that.
You start by applying a layer of fluid to preserve the lightest areas. After painting and letting it dry, you apply more masking fluid to cover the next lightest areas, then paint over that.
This layering method gives you complete control over the highlights, mid-tones, and dark areas.
The downside is that removing multiple layers can sometimes be tricky, especially on rougher paper like Arches. Be cautious about tearing the surface when peeling away each layer.
Combining Pens and Brushes for Masking Fluid Application
Using both a masking pen and a brush lets you switch between fine details and larger areas.
The masking pen is ideal for precise lines, such as fine edges or delicate shapes, while the brush is better for covering broader sections quickly.
The fluid from a pen is typically more controlled and doesn’t spread as much, while the brush can handle larger amounts of fluid for bigger spaces.
This approach helps in creating contrast between fine, detailed areas and larger, masked portions of your painting.
Pitfalls of Combining Techniques
- Overlapping too many layers: Too many layers of masking fluid or tape can damage the paper when removed.
- Removing stencils or tape too late: If you wait too long to remove tape or a stencil, you risk pulling up the paper along with it, especially with heavily textured watercolor paper like Fabriano.
Tools and Products for Effective Masking

Masking Fluid
The first thing that comes to mind when thinking about effective masking is masking fluid. A latex-based liquid, this stuff is essential for preserving those crisp, untouched areas of white paper.
Brands like Winsor & Newton or Pebeo offer reliable options that are smooth and easy to apply. You don’t want to skimp here—cheaper fluids can clump or tear the paper when you try to remove them.
Using masking fluid with the right applicator is just as important. For broader areas, an old synthetic brush will do the trick.
But for more detailed work, a masking pen or frisket pen offers much better control. It’s all about precision when you’re working with fine details in your watercolor painting.
Masking Tape
Masking tape is your go-to for clean, straight edges. It’s especially useful for creating borders or large blocked-out sections where you want to keep the paint from bleeding.
Make sure you use artist-grade tape or painters tape to avoid damaging the paper when peeling it off. Regular household tape is too sticky and can tear the paper.
Pro tip: Always press the edges of the tape down firmly before applying any paint, and ensure your paper is flat, so no water seeps under the tape.
Liquid Frisket
Similar to masking fluid but more fluid-like in texture, liquid frisket gives a bit more flexibility, especially when working on finer, more detailed sections. It’s an excellent choice when you need a more refined application but still want the same resist effect.
It’s also useful when you’re combining techniques, like negative space painting or protecting highlights while working on a complex watercolor wash.
Stencils and Applicators
Masking stencils are a game-changer when it comes to repeating patterns or complex designs. They give you clean, consistent results, and when paired with masking fluid, you can easily protect larger sections of your painting.
Just remember, you need to lift the stencil carefully before the fluid dries completely, or it might pull up the paper with it.
Rubber-tipped applicators or frisket tools are other great tools to have in your kit. These allow for precise application, and unlike brushes, they don’t suffer from bristle clumping. They’re especially helpful when working with frisket or fluid on tight, small details that need clean lines.
Pitfalls to Watch Out For
- Cheap masking fluids: They might save you a few bucks, but they often tear the paper or leave behind a residue.
- Tape that’s too sticky: Even if it’s labeled “low tack,” always test a piece first to avoid peeling off part of the paper when removing it.
- Overapplying fluid: Too thick, and it takes forever to dry, plus it’s more likely to damage the surface when you pull it off.
Removing Masking Fluid Without Damaging the Artwork
Wait Until the Paint is Completely Dry
The first mistake? Rushing. Patience is essential when removing masking fluid. The paint has to be 100% dry, or you risk smudging or tearing the paper.
Watercolor paper—especially textured ones like Arches or Fabriano—is delicate when wet, so any friction at this stage can ruin the surface. Give it time.
Use Your Fingers or a Rubber Cement Eraser
Your fingers are your best tool here. Gently rub the masking fluid with your fingertips, and it should peel away easily without any damage. The key is to start slow, using light pressure.
For more stubborn areas or if you’ve applied multiple layers of masking, a rubber cement eraser works well.
It’s firm but soft enough not to scrape the paper. Just be careful not to overwork the same spot, as this can cause fraying on rougher watercolor paper.
Avoid Using Sharp Objects
Do not, under any circumstances, use a blade or any sharp object to lift masking fluid. It might seem tempting if a corner won’t budge, but you’ll only end up cutting into your artwork or scoring the paper, which will be impossible to fix later.
Remove Masking Fluid Sooner Rather Than Later
Leaving masking fluid on for too long is a common mistake. If it stays on the paper for an extended period, it can harden and become difficult to remove, often leading to tearing or damaging the surface.
Ideally, you should remove it as soon as the paint has dried completely. Waiting too long increases the risk, especially on more delicate or thinner papers.
Pitfalls to Avoid
- Rubbing too hard: Excessive pressure when removing masking fluid can damage the texture of the watercolor paper, especially on softer, more absorbent brands.
- Leaving fluid on for too long: Masking fluid can bond too tightly to the paper over time, causing parts of the paper to come off with it.
Advanced Watercolor Masking Techniques
Layering Masking Fluid for Depth
Layering masking fluid is one of the most effective ways to create depth in watercolor. You start by masking the lightest areas first.
After applying and drying a wash, you mask another section—usually the next lightest.
This process repeats until you’ve built up several layers of paint and masking fluid, preserving each previous layer.
The trick is in the removal. The last layer of masking fluid to go on will be the first one you remove. It’s a bit like reverse engineering your highlights and shadows.
This technique is especially useful when you’re working with detailed compositions that require controlled lighting effects, like negative space painting or highlighting intricate watercolor paper textures.
Using Masking Fluid with Salt for Texture
If you’re after a more unpredictable texture, try combining masking fluid with salt techniques.
Apply a layer of masking fluid in the areas you want to protect, then sprinkle salt over the wet watercolor in the exposed areas.
The salt will pull the pigment, creating organic, crystallized textures while the masked areas stay untouched.
It’s great for landscapes, skies, or water effects. Just remember that salt can damage certain types of watercolor paper if you’re too aggressive with it, so start lightly.
Masking Fluid with Wet-on-Wet Techniques
The wet-on-wet technique in watercolor is tricky enough on its own, but combining it with masking fluid brings another layer of control to the chaos.
You apply masking fluid to the areas where you want a sharp, defined edge—then work wet-on-wet around it.
This is perfect for creating soft backgrounds with sharp foreground elements. The fluid will act as a barrier, preventing color from bleeding into areas you want to stay sharp.
But timing is key. The paper needs to be wet enough for the wash to move, but not too wet that it causes the masking fluid to lift prematurely.
Combining Masking with Dry Brushing
Another way to elevate your watercolor is by combining masking techniques with dry brushing.
After applying masking fluid to the areas you want to remain bright, use a dry brush with a little pigment to create rough, textured strokes in the exposed areas.
The contrast between the sharp edges of the masked areas and the rough, uneven texture of dry brushing can create dynamic compositions.
The key is not to oversaturate the brush, so you maintain the texture you’re after. Watercolor paper with a strong tooth, like Arches or Fabriano, works best for this.
Pitfalls to Avoid
- Masking too early: Applying masking fluid to damp paper will lead to smudges, as it mixes with the paint instead of resisting it.
- Using too much fluid: Overloading areas with masking fluid can tear the paper when removed, especially if you’re layering several coats.
FAQ on What Is Masking Technique In Watercolor Painting
What is masking fluid, and how is it used in watercolor painting?
Masking fluid is a latex-based liquid applied to protect areas of the paper you want to keep unpainted.
You apply it with an old brush or a masking pen to cover details, highlights, or areas of negative space. Once dry, you paint over it, then peel it off.
How do you remove masking fluid without damaging the paper?
After your watercolor has completely dried, gently rub the masking fluid off using your fingers or a rubber cement eraser.
Avoid sharp objects. If masking fluid stays on too long, it can tear the paper, so always remove it sooner rather than later, especially on textured watercolor paper.
Can you use masking fluid with other watercolor techniques?
Yes, you can. Combine masking fluid with techniques like wet-on-wet for sharp contrasts between soft backgrounds and defined areas.
You can also use it with salt effects or dry brushing to create more texture and depth while keeping details crisp and untouched by washes.
What type of paper is best for using masking techniques?
Arches or Fabriano cold-pressed watercolor paper works well with masking techniques. They’re durable enough to handle multiple layers of masking fluid and washes without tearing.
However, always test masking on a small section of your chosen paper, as thinner sheets can rip when you remove the fluid.
How long should masking fluid stay on the paper?
Masking fluid should be removed as soon as your paint dries. If left on for too long, it can bond to the paper and damage the surface.
It’s best not to leave it on for more than a couple of days to avoid difficulties during removal, especially on delicate watercolor paper.
Can masking fluid be used on wet paper?
No, it’s important to apply masking fluid to completely dry paper. If the paper is wet, the fluid will smear or spread unpredictably.
Always wait until the paper is dry before using masking fluid to preserve clean lines and edges.
What brushes are best for applying masking fluid?
Old, synthetic brushes work best for applying masking fluid. Never use your good watercolor brushes.
Masking fluid can destroy bristles, so you’ll want to keep specific brushes just for this purpose. Some artists also use rubber-tipped applicators or frisket pens for more detailed work.
Can you dilute masking fluid for easier application?
Yes, you can slightly thin masking fluid with water, but be careful. Adding too much water can reduce its ability to block watercolor effectively.
Thin it only if the fluid is too thick for fine details, and make sure to mix it thoroughly before applying.
What are some pitfalls to avoid with masking fluid?
Don’t leave masking fluid on the paper too long, as it can tear the surface. Also, avoid applying it too thickly, which makes removal harder.
Be careful when using it on soft or low-quality watercolor paper to prevent damage, and always ensure the paper is dry before applying.
Can masking techniques be used for large areas?
Yes, masking tape or masking fluid can be used for large areas you want to protect. Masking tape works best for straight edges, while fluid is better for irregular shapes.
Just make sure to press the edges down to prevent any bleeding of the watercolor under the mask.
Conclusion
Mastering what is masking technique in watercolor painting opens up countless possibilities for creating detailed, controlled artwork.
Whether you’re preserving highlights with masking fluid, blocking out large areas with masking tape, or using more advanced tools like frisket pens, each technique has its own role in enhancing your control over the final piece.
By understanding how to apply these techniques effectively—knowing when to use liquid frisket, how long to leave masking on the paper, and how to remove it without damaging the surface—you’re able to add clarity and depth to your work.
This not only helps protect your watercolor paper but also allows you to manipulate light, contrast, and texture.
Experimenting with these techniques will strengthen your command over complex watercolor effects, making your paintings not just more professional, but more intentional.
Just be sure to avoid common pitfalls like tearing or improper removal, and always choose the right masking tools for the job.