Underpainting for Beginners: EVERYTHING You Need to Know

If you've ever wondered what an underpainting is and why so many painters swear by them, this video is for you. Used by both beginners and pros alike, this is a step that will consistently make a significant difference in both depth and value, because it locks in your lights and darks before you even touch color. In this video, I'll show you exactly what an underpainting is, why you need it, and how to build one using acrylics, which you can use whether you paint in acrylic or oil. First, let's talk about what an underpainting is and why I love them. An underpainting is a thin first layer of paint that establishes your values, composition, and main forms. Unlike a sketch, which is just an outline, it starts building depth right away by locking in where your values are, which is how light or dark a color is. I also find underpaintings much easier to see than a pencil drawing, which I personally have a tendency to accidentally paint over. In general, I use underpaintings for landscapes because setting up a value structure really helps build that sense of depth and atmosphere. However, you can use underpaintings for any subject you'd like. Traditionally, underpaintings are done in a single color, either a gray, called a grisaille, or a brown, called a brunei. Today, I'll be using burnt umber, which is my go-to, and I'll be using glazing fluid to adjust the transparency. I'll be using acrylic paint for this, since it dries so quickly, and even if you're an oil painter, you can still paint on top of acrylic, just not the other way around. Sometimes you might see artists using white to lighten their mixes, or wiping away parts of their underpainting to create the full range of values, but since the piece that I'm going to be demonstrating today doesn't have that many highlights, I'm just going to use burnt umber throughout. Here's how we'll do it. Here's how burnt umber looks straight out of the tube, in terms of opacity and value. Now, I'm going to add a little bit of the glazing liquid, which increases the transparency of the paint. I'm going to keep adding more and more, which reduces the pigment load each time, until we're left with a nice, transparent wash. This will be how I control the values in the underpainting. Now, you might be asking, why not just use water to thin the paint, instead of glazing fluid? Let me show you why this is not a good idea. Too much water means that the pigments will be swishing around, which makes it harder to control and more likely to drip. Glazing liquid still binds the pigments and keeps both the color and the consistency the same throughout, so you don't have to worry about the pigments pooling or traveling to where you don't want them. Now, if you're finding this useful and are just getting started with acrylics or oils, and you want to build a solid foundation, I've written some free ebooks on both mediums that you can download. They are linked in the description below. Now that you know how to adjust burnt umber, let's go through how to create an underpainting step-by-step. To create your underpainting, you'll need a canvas, your reference photo, burnt umber paint, and glazing fluid. I'll be working on a canvas with a colored ground, which is a tinted base layer. Now, this isn't the canvas that I did my underpainting on, but here's an example of what a colored ground looks like. I use a colored ground because it eliminates white, which makes it easier for me to read my values and adds warmth and harmony. If you'd like to go over colored grounds in greater detail, I have a full step-by-step tutorial on how to apply one linked above and in the description, but let's just go over it quickly here. To prepare a canvas with a colored ground, mix gesso with liquid acrylic paint and a small amount of water to make it easier to spread. My favorite color is yellow ochre, but any warm, neutral works. Apply it with a foam brush, which won't leave brush marks, then sand lightly once it's dry. I usually repeat this two to three times for a smooth, even ground. So when you're done, your canvas should look like this, and I typically prepare several canvases at once. Now let's look at how to transfer the drawing. Getting the drawing onto the canvas can be such a source of anxiety for so many artists. I'll be teaching the grid method today, but I don't think there is anything wrong with using a projector or tracing. Some artists worry that using tools like that might be considered cheating, but I think it's more important to not let the drawing hold you back from painting. The reason that I'm teaching the grid is because anyone can use it, regardless of your home setup. First, make sure that your photo is cropped to match the aspect ratio of your canvas. The aspect ratio is just the relationship between the width and the height of your canvas. I'm going to be working on an 18 by 30 inch canvas, which is a three to five aspect ratio. So my photo is cropped at three to five to match. Then divide your photo into equal squares using that ratio. So in my case, that's three across and five down. Now, if you're using a digital reference photo instead of a printed copy, the Grids app on the iPad will add an overlay for free. Now add that same grid to your canvas with a colored pencil. Since my canvas is 18 by 30 inches, each box is six inches square, giving me a three by five grid that matches my reference exactly. I use a colored pencil for this instead of graphite since it won't smudge or tint the paint. Now that the grid is set up, I'm going to add the underpainting directly onto the canvas. Now if that feels intimidating, you can absolutely do a rough sketch with a colored pencil first. I'm going straight to paint because it saves time, but do whatever works for you. I'm going to start off with a ton of glazing fluid to dilute the paint so that it's nice and light in case I make any mistakes. I usually start with the most obvious shapes that I can see in the composition, so in this case, the trees near the middle. I'm also referring to the grid constantly, and whenever I make a mistake, I'll just take a wet q-tip or piece of damp paper towel and erase it. You can also use this method to wipe back any paint that goes on too dark. When you're doing an underpainting, I find it helpful to ignore what you know about the object you're painting and instead only see forms and values. So instead of thinking, that's a tree, think, that's a tall dark shape with sections coming off of it. It's almost like turning off that part of your brain and painting what you see, not what you know. Once the basic shapes are in, I can start adding darker values. To do this, I'm just squinting and adding in the dark forms that I can see. I'm not overthinking or trying to make it perfect, I'm just adding chunks of dark. Painting dense forests can be really hard, but instead of trying to add branches for every single tree, I'm focusing on adding in negative dark spaces, which are the dark areas between the branches. I find that's easier for me to see rather than the branches themselves. Moving on to the misty part in the back, I've diluted my paint with tons of glazing fluid again. In landscapes, the farther away an object is, the lighter it is, which creates that sense of depth. I'm really not too worried about creating every single tree here, more just the overall shape of the background. Occasionally, I'm going to add in a slightly darker tree just to keep things interesting, because otherwise the background becomes a solid wall. As I continue to work, there are a few more things that I want to share with you if you're working on your own underpainting. First, this is not going to be perfect. As I was working on mine, I realized that my horizon line wasn't as straight as it should be, and that I made my darkest section too dark and too messy. But it is much better to figure out problems like that in the underpainting, then adjust them in the first layer, instead of trying to get the underpainting itself perfect. As artists, it's important to be efficient and spend time on what will actually matter the most to your painting. So try to resist the urge to go crazy on the details at this stage, especially when you know you'll be painting over it. Something else that you may find is that the underpainting will actually boost your sense of confidence. Imagine that this was only a drawing on the canvas, showing the outlines of everything, but no values. For this particular painting, that would be super intimidating, because there are so many subtle value and color shifts. And without the underpainting, I'd be trying to figure out all of that at the same time as adding in color. As the underpainting comes together, you can actually visualize the final painting and see how it's going to develop. If there are any areas that you're struggling with now, you can make a mental note to start working out how to approach them when it's time to add color. Making a plan for tough spots means that you're less likely to get frustrated and quit. From start to finish, this entire underpainting took me about 90 minutes, and for me, it was entirely worth it. Not only will you feel more confident about starting, your painting will automatically have way more depth and intensity, as opposed to working on a pure white canvas. If you're ready to try an underpainting but are feeling a little intimidated, you can always do a quick study first before tackling a larger canvas. For this piece, I took 10 minutes and created one on a plain white canvas board, and just doing that broke the ice. You can also use a sketchbook or watercolor paper to test it out. Now, as I mentioned before, this is not perfect. This is too dark, this isn't straight, but that's okay. I can fix all of that when I add in color, and now I'm ready to get started. Now, if you have any questions, drop them in the comments below, and if you want to keep building your skills, I have linked my canvas prep and colored ground tutorials here, so you can check those out next. Don't forget to grab your free ebooks, and happy painting!