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How to Prepare Watercolor Paper?

how to prepare watercolor paper

Watercolor beginners typically do not know that they are supposed to prepare the paper they will be using beforehand. If you are one of them and still unsure how to prepare watercolor paper and how to choose the paper to use, this article is for you.

From here on, you will be learning the steps in preparing the paper for watercolor paintings. You will immediately notice a significant improvement in your work after just a bit of prep work.

Why Do You Need to Prepare Watercolor Paper?

Before you learn how to prepare watercolor paper, do you know why you need to do it? Well, the main reason why you need to prepare watercolor paper, otherwise called “stretching”, is to avoid “cockling”. It happens when the paper wrinkles and curls up when it gets wet, which is what will happen when you use watercolors.

A good quality watercolor paper is 100% made of cotton fibers and the methods used in manufacturing them make the fibers align parallel to each other. When the paper gets wet, the fibers expand lengthwise.

Their alignment also gets skewed in every direction. When the paper dries, the fibers contract back to their normal length. However, the fibers retain their skewed alignment.

This change in the fibers’ alignment is the reason why the paper has hills and valleys in the center. The edges curl up when it dries. Stretching the paper before applying watercolor will prevent buckling from happening.

There is another reason why you need to prepare your watercolor paper – that is the chemical known as “sizing”. Sizing is a chemical additive in commercially-made paper to alter the way it absorbs water and adds to its texture.

Left as it is, untreated drawing paper acts just like a paper towel. This means it is very absorbent. Sizing is applied so that the paper does not suck up all the paint you apply to it. However, this can be troublesome for watercolors because the sizing creates an uneven color application.

Stretching the paper will allow you to dissolve most of the sizing and redistribute it more evenly across the surface. They can also make the paper more receptive to watercolors. You can tell how uneven the sizing is on a piece of paper when you try making a wash and the watercolor leaves blotches all over.

Step-by-Step Guide

What to Prepare:

  • A tub that is big enough to fit the paper you will be stretching
  • Board for stretching the paper
  • Gum tape for fastening the paper to the board

Detailed Steps:

Step 1: Pick the paper

why do you need to prepare watercolor paper

It is recommended that you use acid-free paper. Acid makes the paper brittle over time. Sometimes, it would be so brittle that it disintegrates when you hold it. Acid-free paper can virtually last forever.

You should also use the heaviest sheet of paper that you can afford. The thicker the paper, the more robust it will be. It will also be less likely to bend or curl when put in storage.

Step 2: Pick the Board

Using a board is the most popular way of stretching paper. One made of spruce is ideal. Spruce wood is durable and resistant to mold, which is very important because it will get quite wet. However, spruce is quite hard to find.

You can also use medium-density fiberboard (MDF), but you need to seal the ends and all over to make it significantly less absorbent. For paper that is less than 24” square, you will need to use a board that is at least 12mm thick.

Step 3: Submerge the Paper in water

Fill a large enough container with clean water. It should at least be big enough for the paper that you will be stretching.

When cutting the paper to size, you should allow one inch on all sides for the gum tape. You should proceed to dunk and submerge the paper under the water. You can roll or fold the paper as necessary to let the water seep through the fibers.

The length of time you need to keep the paper submerged will depend on the weight of the paper. For instance, you have to submerge a 640gsm paper for at least 15 minutes.

Step 4: Mount the Paper on the Board

Attach one end of the wet sheet of paper on the board. Using gum tape ensure that you firmly stick the edge of the paper on the board. Roll out the rest of the sheet of paper, and then hold down the opposite side using gum tape as well.

You can dry two sheets of paper at a time using both sides of the board – that is if it is thick enough. You also need to prop the corners of the board on four small bottles or jars to give the paper at the bottom enough ventilation to dry properly.

Make sure that the paper is completely flat and that there are no air bubbles trapped in the middle. You can use a soft sponge to flatten out the paper and squeeze out any air pockets.

Step 5: Remove the Paper from the Board once Dried

Usually, the paper will be completely dry after 24 hours. However, it might take a bit longer depending on the thickness of the paper. You can test by running your finger over the surface of the paper. If it still feels damp, you need to let it dry properly.

Once dried, remove the gum tape and then cut the paper down to the size you need. It is not advisable to use a hairdryer to speed up the drying process. The paper should dry out on its own to ensure that the paper contracts evenly across the entire surface.

Using a hairdryer can cause some parts to dry quicker, which will deform the arrangements of the fibers in the paper.

Helpful Tips:

  • Do not let the paper soak for too long – If the paper gets too soaked, even if you managed to fish it out and it is still in one piece, you will have regrets. The reason is that soaking the paper too long will make it expand more. If it contracts, it might tear once it gets dry
  • Take note that you can also use regular masking tape, a heavy-duty stapler, and the like, aside from gum tape


Now that you know how to prepare watercolor paper, you will find out how much of a difference it makes to your usual art projects. Aside from the paper not buckling and curling anymore, it will seem like you can lay down more color than before.

Yes, it does take quite a lot of time and effort to prepare the paper for watercolor, but it will be worth it in the end.

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