You’ve put the finishing touches on your watercolor painting, but now you’re wondering about what to do about the pencil drawing.
Should I erase the pencil drawing in my watercolor painting? I don’t recommend erasing the drawing because it’s difficult to erase once you paint over it. This is true even when you just wet the paper with plain water. If you prefer to erase the drawing, then draw faintly so the pencil lines are easier to erase.
In this post, I list all of the advantages of allowing the pencil lines to show through in your watercolor painting. I explain why it can be more difficult to erase the drawing after you paint over it. Finally, if you prefer to erase the drawing, I offer some tips on what pencils and erasers to use to make that easier.
The Advantages of Leaving the Drawing in a Watercolor Painting
Most of the watercolor painters that I admire leave the pencil lines showing in the finished painting. In fact, some of them use a very soft and dark pencil so that the lines will be more evident in the final painting. This is a preference, but below are the reasons why you may want to put your eraser away.
The Pencil Drawing Will Add Details to Your Painting
Watercolor paintings consist mostly of washes of color that allow you to create a wide range of shapes. However, it can be difficult to draw thin lines with a watercolor brush.
Yes, there paint brushes that you can use to draw in the fine details, but it’s not as direct as drawing with a pencil.
Sometimes the painted lines stand out too much, especially if the color is too dark. Pencil lines are more subtle. The graphite is gray and the edges of the pencil lines are fuzzier than a line painted with watercolor.
Of course, it helps to have this strategy in mind when you begin a painting. Think about the details that you want to handle with the pencil drawing before you begin.
Using the drawing for details can save a lot of time. You can create the structure of the painting with the pencil marks, and then use washes of watercolor to add color and value.
Sometimes I draw with ink to make the lines stand out even more. Below is an example of this technique.
You Won’t Risk Damaging the Painting With the Eraser
Watercolor painting can be nerve racking because there are plenty of opportunities to ruin a painting.
Erasing the pencil lines from a watercolor painting is another opportunity to damage the painting. For one, you can damage the paper if you erase too aggressively. Watercolor paper is tough, but it can only handle so much erasing. Drawing paper is even more susceptible to damage, which is why I don’t recommend it for watercolor painting. You can read more about this in my post Can You Use Drawing Paper for Watercolor.
If you use a dark pencil for the drawing, the lines may not erase entirely. This is especially true with rough watercolor paper because the graphite seems to cling to the texture of the paper more so than with smooth paper.
Half erased lines can look fussy, or unintentional. When you leave the drawing intact, the lines look confident. Half erased lines might look like you failed at erasing them, especially if they smear.
You may also scuff the paint a little as you rub the eraser over the surface of the painting.
It’s Faster and Easier to Not Erase the Drawing
I don’t know about you, but I prefer to eliminate any unnecessary busywork when I’m painting. Instead of removing the evidence of your drawing, I say leave it alone. You can spend the extra time working on the next painting.
The underlying drawing can be beautiful in itself, so why not show it off?
When you paint with a fine brush you have to frequently reload it with paint. This takes more time than working directly with a pencil.
The Advantages of Erasing the Pencil Lines in a Watercolor Painting
Perhaps you like to paint in a photorealistic manner and you find the pencil lines are distracting.
Watercolor isn’t very forgiving–you don’t get many second chances. The pencil drawing will allow you to work out the proportions and the placement of the shapes before you begin painting. When you complete the drawing, you will be able to focus on the color and value instead of the drawing.
So, the drawing stage is important, but perhaps you don’t want it to show in the end result. Below are some ideas on how you can draw on watercolor paper and still be able to erase it when you’re done.
Tips for Eliminating Pencil Lines in a Watercolor Painting
If you want to be able to erase your drawing from your watercolor painting, then it’s important to draw with light lines. Dark lines are very difficult to erase without damaging the paper.
If you happen to scuff the paper with the eraser, it will leave a blemish in the painting. Drawing with light lines will make them easier to erase, and you won’t have to use as much pressure to remove them.
Avoid the pencils with softer leads. Drawing pencils are graded by the hardness of the graphite. Drawing pencils that have a “B” after them such as 2B, 3B, 4B contain soft graphite. Softer leads leave darker lines and are more prone to smearing.
I don’t recommend using watercolor pencils if you want to erase them later. While the “lead” is designed to be water soluble, the water won’t erase a line drawn on paper. In fact, the color seems to get more intense as you wet it. It also spreads into other sections of the painting as you brush over it. See the erasing test in the next section for an example of this.
The same is true for pencils that contain soluble graphite. Adding water to the line doesn’t erase it, but it does spread it around.
Perhaps you may be able to get this to work if the paper you’re using contains a lot of sizing. The action of painting over the lines may dissolve and lift them. I haven’t tested this though.
Erasing Tests on Watercolor Paper
Here are two tests that I conducted on two different types of watercolor paper. I drew a series of lines with pencils of various hardnesses. I’ve included watercolor pencils, water soluble graphite pencils, and red transfer paper.
I drew 2 lines with each pencil, a dark line and a lighter line.
Then I wet the right half of each test with plain water. When the paper was dry, I used a kneaded eraser to erase the lines down the center. The side that I applied water to was more difficult to erase.
The paper is Arches rough watercolor paper, and Fabriano Artistico cold pressed watercolor paper. You may assume the smooth, hot pressed paper would erase better, but both produce similar results.
However, the lighter lines were easier to erase. So, if you want to erase your drawing from your watercolor painting, make sure your lines are light.
Even if you can’t totally erase the drawing, it won’t visible in the darker areas of your painting.
Why You Can’t Erase the Pencil Drawing in Your Watercolor Painting
The reason why the pencil drawing is difficult to erase from a watercolor painting is because the binder in the paint acts like an adhesive. The sizing on the paper may also act like an adhesive when it gets wet. It softens with water and the graphite sticks to it when it hardens.
Watercolor Paint Contains Gum Arabic
The binder in most watercolor paint is gum arabic which is what makes the pigment adhere to the paper. Gum arabic is a natural gum that comes from acacia trees. The binder is what makes the pigment stick to the paper.
So, when you paint over a drawing with watercolor paint, it’s like painting over it with a thin layer of glue. When it dries, the paint acts like an adhesive and binds the particles of paint to the fibers of the paper, along with the graphite particles.
Why Wetting the Paper Makes the Drawing Difficult to Erase
Just wetting the paper with plain water will make the pencil drawing more difficult to erase when the paper is dry. If there’s a problem with the drawing, it’s best to erase it before you wet the paper.
One of things that I realized is that manufacturers coat the paper with a sizing that prevents the paint from soaking into the paper too quickly. Gelatin is usually what the manufacturers use to size watercolor paper. So, when you wet the paper, the gelatin sizing softens up and the graphite sticks to it as it dries.
To test this theory, I examined a pencil line under extreme magnification. I assumed that applying the water to the paper would drive the graphite deeper into the fibers of the paper. But when I examine them under high magnification, I don’t see much difference. In fact, some of the graphite appears to have washed away in the second photograph below.
In the third photograph below, I used a kneaded eraser to erase the line after the paper was allowed to dry. Some of the graphite remains stuck to the fibers of the paper.
The fourth photograph is a separate line that I erased without wetting the paper. Almost all of the graphite is gone.
What type of eraser should I use to erase the drawing in a watercolor painting? A kneaded eraser is the best eraser for removing lines from a watercolor painting. It’s rubbery so you can knead like dough or putty. This type of eraser won’t leave crumbs behind as you erase the lines. You can also shape it to form a small point that you can use to get into smaller areas of your painting.
Can watercolor go over pencil? Watercolor can go over pencil drawings. For the best results, you’ll want to draw on watercolor paper and use a pencil that doesn’t smear. Applying watercolor to drawing paper may cause it to buckle. The paper may also start pilling if you work it too much with the brush.
Can I erase watercolor pencils? You can use an erase to lighten the lines but it may not erase completely, it depends upon the pigment. Another option is to try and lift it by scrubbing it with a wet brush.