How to Flatten Watercolor Paper After Painting

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If you are new to the world of watercolor painting, you may be wondering how to flatten the paper once you have finished painting. I have found that no matter how much or little water you use, the paper is going to warp and buckle a bit (sometimes a lot).

It is pretty safe to say that you are not going to be able to, or even want to frame a watercolor painting that is warped. But, there are a few ways that you can fix this problem after you finish painting.

There are also a few things you can do before you paint and while you are painting that will help to keep the paper from warping too much. This will make it easier to completely flatten out when the painting is finished.

Today I am going to give you some advice that will help you to get your watercolor paper nice and flat so that your paintings are ready to frame.

Before You Begin Painting

There are a couple of steps you can take before painting to ensure that your watercolor paper isn’t going to warp a lot. The more you can do before the painting is finished to prevent warping, the less work you will have to do once you have finished the painting.

#1. Use Painters Tape

Before you begin painting, it is important to use painter’s tape or masking tape to hold the watercolor paper in place. Not only is this going to keep the paper from moving around while you paint, but it will also help to prevent warping and buckling.

Make sure that you tape all around the outer edge of the watercolor paper. Do not leave any gaps, because the paper will warp in the areas where there is no tape.

The only drawback to using tape is that it can be difficult to remove. You must be very careful when removing the tape, or you will pull a layer of paper off with the tape.

I suggest using a hair dryer on a low setting or a heat gun. This will soften the glue on the tape and make it easy to pull away from the paper without damaging the paper.

#2. Don’t Use too Much Water

If you will be working with the wet-on-wet technique you will need to wet the paper before painting. Many beginners end up using much more water than they need for this purpose.

You don’t need to completely soak the paper. Just use enough water to make the paper damp. You will know if you have used too much water because you will see it pooling on the paper.

I suggest using a spray bottle rather than a brush when wetting the paper. Set the sprayer so only a fine mist is coming out.

#3. Use Heavy Paper

The heavier the paper, the less likely it will be to warp. Some artists also stretch their paper, but I find this is one extra step that I don’t always feel like doing.

Instead, I use 140-pound or heavier paper. There will still be some warping, but not nearly as much as there would be if you were using lighter paper.

Flattening Watercolor Paper When the Painting is Completed

When I first began using watercolors, I asked an artist friend how to flatten out my paintings before framing them. She suggested that I place them under something heavy, such as a pile of hardcover books. Be sure to spritz the painting with a fine mist of water before placing it under the books.

This does work, but it can take several weeks or even months. Even after leaving the painting beneath the books for a long period, the paper will still be a bit warped. If you put a piece of cardboard on either side of the painting, it will help to absorb some of the water.

Let’s take a look at some ways to get rid of the warping without having to wait forever to frame your painting.

#1. Hang the Painting to Dry

One method I have had success with is hanging the painting to dry once it is finished. If you have used tape to hold the painting in place while you work (which you should always do), there will be a white border around your work.

I like to use clothespins or binder clips attached to the white border. Make sure that you only use clips on the border so you don’t damage the painting.

Hang something heavy from the bottom of the painting, such as small weights. This will pull the paper from the bottom and remove a lot of the warping because it stretches the paper.

#2. Use an Iron

Students usually ask me if they can iron watercolor paper to unwrinkle it. The short answer is yes.

Another method I have used to get rid of warping is to iron my paintings with a regular clothing iron. This is something that you need to be very careful with.

Always use the lowest heat setting. After all, you don’t want to end up burning the paper and ruin your painting.

Place the wrinkled paper on a flat surface, and cover it with a clean towel. Then you can iron over the towel without the risk of burning the paper.

Another way to use the iron is to iron the towel or another piece of cloth first. Then you can lay the hot cloth on top of the painting.

Leave the cloth in place for a minute or so. Then, gently peel the cloth away from the paper. Give the paper enough time to cool.

If there is still a bit of warping you can then place the painting under a stack of books or something else that is heavy for a few days.

How to Keep Watercolor Paper From Curling

To prevent watercolor paper from curling, you can follow these tips:

Stretch the paper

Wet the entire sheet of watercolor paper by soaking it in a tray of clean water or by using a spray bottle to dampen both sides. Then, secure the wet paper onto a drawing board or a flat surface using tape or clips. As the paper dries, it will tighten and remain flat.

Use heavyweight paper

Opt for watercolor paper that has a higher weight or thickness, typically measured in pounds (lb) or grams per square meter (gsm). Heavier paper is less prone to curling and can handle more water without warping.

Pre-wet the paper

To stop paper from curling when painting, before starting your painting, dampen the surface of the watercolor paper with a clean, wet brush or a spray bottle. This helps the paper fibers expand evenly and minimizes the chances of curling.

Tape the edges

Secure the edges of your watercolor paper to a board or a flat surface using painter’s tape or masking tape. This helps keep the paper flat and prevents it from buckling as it dries.

Work in stages

If you’re using a lot of water or applying multiple washes, allow each layer to dry completely before adding the next. This gradual drying process reduces the risk of excessive moisture causing the paper to curl.

Store artwork flat

Once your watercolor painting is complete and fully dry, store it flat between sheets of acid-free paper or in a portfolio. Avoid rolling or folding the artwork, as this can cause permanent creases and curls.

By following these tips, you can minimize the curling of watercolor paper and ensure your artwork remains flat and presentable.


There are a few types of watercolor paper. Unless you are using the heaviest watercolor paper, chances are your paintings are going to be a bit warped. Don’t panic, because this is something that can easily be fixed.

If, after you have tried the methods I talked about today and there is still a bit of warping, don’t worry about it. You can always tape the painting to a mat before framing it.

I wouldn’t do this if I was going to sell a painting, but if it is just something you have done for yourself, no one will ever know that you have done this.

Check my guides on watercolor painting techniques and watercolor painting tips for more details.

*image by Tihon6/depositphotos