Masking a Watercolor with Masking Tape by Lorraine Watry

Masking tape is my favorite way to mask a watercolor.

For those that are just starting out with watercolor, masking is a way to protect areas of your painting, while you paint around them. Then the mask can be removed and you can leave those areas white or you can paint them.

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There are two ways to mask a painting, masking fluid or masking tape. Masking fluid is a liquid latex substance that can be painted on your paper, canvas, Yupo, or clay board. You have to carefully apply it to get clean edges and so that it completely covers the shape you are protecting. After you are done painting around the masked area, the masking fluid is removed by rubbing it off or by using a rubber cement pick up tool. Using masking tape as a mask for watercolor is done by laying down a strip of masking tape over your shape on your watercolor paper and then carefully cutting around it to protect that shape. Masking tape works best on watercolor paper, less so on the canvas, Yupo, and clay board surfaces because the paint can seep under the tape if it is not sealed well.

There are a few of things to know if you are going to use masking tape to protect areas of your painting.

  1. Not all watercolor papers, even the professional grade papers, can handle masking tape on their surface. Some papers will tear when you are removing the masking tape. I found all pulp based papers (most are student grade) and even some cotton papers, will tear if you use masking tape on them. So, test your watercolor paper prior to using the masking tape on a painting. I use Arches, 140 lb. cold press paper and the masking tape works just fine on this paper. NOTE - If you use an Arches watercolor block, test the masking tape on a spare piece because a couple of my students had issues with their Arches paper from a block tearing. The Arches blocks may have a different amount of sizing and it may not hold up to the sticky masking tape.

  2. Make sure to use a super sticky/high adhesive masking tape because the water and paint will seep under tape that is not attached well to your paper. I use the Scotch brand masking tape #2020 from the paint department at Home Depot. It says “High Adhesion” on the inside label and pro painter on the box or shelf. You may be able to purchase this tape online if you don’t have a Home Depot near you.

  3. Use a SHARP blade to cut the tape. I know it may seem counter intuitive to use a sharp blade because you don’t want to cut through your watercolor paper, but the sharper the better. With a sharp blade you need very little pressure to cut through the tape. If your blade is dull you will press harder and can groove your paper causing the paint to make dark lines in these areas or you might press hard enough to cut through the watercolor paper. I use a snap-able, 9mm blade from Home Depot (paint dept.). This blade is inexpensive and can be refilled with new blades. When you need a new blade, you just snap off the previous blade and push up the new blade. (see image above)

  4. You can see your pencil line through the creamy colored masking tape. So, you don’t need to draw your lines extra dark. If you click on the images in this post, you should be able to see my pencil lines under the tape. There are other colors and brands of masking tape, even some with an edge sealant (like Gorilla tape). I don’t use the other colors because they can be hard or impossible to see my pencil line and I don’t want any added sealants on the tape because I don’t know what this might transfer to my watercolor paper. Those sealants might cause issues with my paint or paper down the line.

My Process for Masking this Watercolor:

For the painting in this post, I used both masking tape and masking fluid.

After drawing my image onto the watercolor paper, I stretch my paper onto my board. You can see how to stretch watercolor paper on my YouTube video at this link: How to Stretch Watercolor Paper and Transfer a Drawing

After stretching my paper, I wait until it is completely dry, sometimes I have to wait over night. You can tell if your paper is completely dry if it doesn’t feel cool to the touch. If you apply masking fluid while the paper is wet, the fluid will spread instead of staying in the shape you are masking and could adhere to the paper fibers and tear the paper when you go to remove it.

Where I Use Masking Tape or Masking Fluid on My Watercolors:

When my paper is dry it is safe to apply my masking tape and masking fluid. I use the masking fluid in small areas that might be hard to cut around if I were to use masking tape. I like using the masking tape to cover large areas, in this case the swan needed to be protected so that I didn’t get my background colors on the white bird and to make painting around the bird much easier.

Using the blade with the masking tape can be a little tricky at first, especially around curved shapes. As I said before, you need to use a sharp blade. I give the blade very little pressure as I follow my lines to cut around the shapes. I place one piece of tape at a time and cut it, then overlap the next piece of tape by about 1/8 to 1/4 of an inch. The Scotch brand tape comes in 3 sizes and I use the size that will cover the most area or that fits the shape with the least amount of waste. Some of the tape I cut off a shape is usable in another area, so I hold onto the bigger off-cuts until I know I won’t need them.

While I am cutting the tape, I found that I have to turn the paper or angle my blade a different direction to be able to see my drawing under the tape. As I have used the tape more and more, I am able to cut more precise shapes and smaller shapes. After I have cut all the tape, I go back over the tape with my fingers and press it down again to make sure that all the edges are sealed. I don’t want any paint seeping under the tape. I don’t leave the tape on the paper for very long. I think the longest I’ve left it was a month and that is pushing it because the glue that is on the tape can start transferring to your paper and causes a sticky mess.

The Reason I like Masking Tape Over Masking Fluid:

I used masking fluid only for many years. However, now my favorite way to mask a watercolor is to use masking tape.

Masking fluid takes longer to apply and if I was not careful, I would end up with messy edges or openings in the mask that I got paint on. Shapes that were protected with masking fluid usually need some clean up after I remove the mask because the shapes usually aren’t exactly as I want them and they look rough and out of place with the rest of the painting. So, I would have to go in with paint to clean up the edges or a scrubber to soften and change the look of the shape.

Masking tape will give me a very clean edge (as long as I cut carefully) that doesn’t need any clean up when I remove it. As long as I use “High Adhesion” masking tape there shouldn’t be any paint on my shapes when I remove the tape.

See this Full Watercolor Demo in a Future Magazine Article:

This painting will be published in an article that I am doing for International Artist Magazine. This is only a portion of the full painting. The article will include a step-by-step demonstration of the complete painting.There is no date yet for the article, but if you sign up for my newsletter, I will announce when the article is available in the Magazine.