Digital Art Shading for Dummies
Shadows are formed when an opaque body comes into contact with light from a light source. We often think of the Sun and lightbulbs as the chief sources of light, producing photons when the atomic electrons are excited by way of heat. The truth of the matter is that all visible objects are sources of light. As light bathes the Earth, all objects reflect light, with what we know as color being the different electromagnetic wavelengths formed when light collides with stop STOP STOP.
It happens every time. Click a video on YouTube about shading – any video – and 0.5 seconds in they start throwing words like “refraction” and “occlusion” at you. I’m not a scientist; I don’t know what all them big fancy words mean. I just wanna draw cartoons, for God’s sake.
Here's what I know about shadows as a newbie - 1: they exist, and 2: they go where the light doesn't cuz something's blocking it.
Let's just get right to it. I'm using Paint Tool SAI 2 for all this, but I think (or at least I hope) most other drawing programs like Photoshop or Krita have the same or similar tools.
Shading and Highlighting in Paint Tool SAI
The shading stage usually comes after the drawing has been colored in, when artists add shadows and highlights to the person or thing they've drawn. "Shadows" are areas where the light isn't hitting, and "highlights" are areas where the light is hitting most directly.
Here's a little blue circle I've made in Paint Tool SAI 2. Right next to it, I've drawn a little Sun.
I reckon the shadow will be on the opposite side of where the Sun is, and the highlight will be right underneath where the Sun is.
I draw shadows on a new layer above the base color. I make this layer a clipping group, so it only paints on top of the layer underneath. Then I change the layer mode to "multiply" and drag down the opacity to something like 50% or 25%.
"Multiply" just means "darken" when it comes to layers. You use a multiply layer when you want to make things darker.
Now when you draw on this layer, you'll see it darken the layer underneath.
When you're drawing in shadows, you can either just draw it directly on top with the pencil tool, or you can use the lasso tool to mark out an area you want to darken and fill it in with the bucket tool.
Highlights work in mostly the same way, except instead of a multiply layer, most artists use the "screen" layer. The screen layer does the opposite of the multiply layer and makes the picture brighter.
Very often you'll find that the highlights aren't as big as the shadows. Many times they might just be a couple of dots to indicate a little glimmer of light.
Put them together and you'll get something like this:
Notice as well that the shadow follows along the shape of the object - it's curved just like the circle.
As far as I know, cubes are shaded a little differently - each face is one big block of darker or lighter color. But when it comes to characters, I think the shadows on them will be mostly curvy.
What Color are the Shadows?
Let's take a look at three different ways of coloring shadows and highlights, in the order I think looks least-to-most appealing:Level 1 Shading
To me, something about this looks kind of harsh. The pure black doesn't really blend in with the blue - it's like we just put a completely different color next to it (which, essentially, we did).
If you do want to use black for shadows, I recommend making them completely black with no change in opacity. This is the effect you get from Mike Mignola's work - he draws stark black shadows on his characters before he adds color to them, resulting in a menacing stylized look.
Level 2 Shading
Here the shadow is a darker shade of the same blue the circle is, and the highlight is a lighter shade of the same blue.
It’s a subtle difference, but if you put this one side-by-side with the black-and-white one, you’ll see this one looks a lot more natural. The shadow and the highlight are a lot bluer and less harsh.
Level 3 Shading
Here the shadow and the light are actually different colors entirely – the shadow is a dark navy blue, and the highlight is a greenish aqua. These two colors live right next door to blue on the color wheel ("analogous colors" are colors that sit next to each other on a color wheel) .
As you can see, this makes both the shadow and the highlight look even bluer. It looks very bright, very natural and very pleasing to the eye.
Using Warm and Cold Colors
The "level 3" circle uses a "cold" color for the shadow and a "warm" color for the highlight. Artists tend to split colors into warm colors and cold colors. The warm colors are pink, red, orange and yellow, and the cold colors are purple, blue, cyan and green. On the Paint Tool SAI color wheel, the warm colors are mostly on the left-hand side, and the cold colors are mostly on the right.
In shading, shadows tend to be “colder” and highlights tend to be “warmer”. So if our base color is green, we get our shadow color by taking that green and nudging it over to the colder cyan, and we get our highlight by nudging it over to the warmer yellow.
Of course, we don’t draw these colors onto the base directly. We make two clipping layers – one for cyan shadow, one for yellow highlight – then turn the shadow one to multiply and the highlight one to screen.
To be fair, the bright cyan is a bit hard to see on a multiply layer. Let’s change that to a darker cyan in the color cube.
Using Just one Color for Shadows
Honestly, when it comes to cartoons, I’ve seen most artists just stick with one color for their shadows, and nine times out of ten that color is a very dark blue. You’ll rarely come across anything that’s completely black or white in nature – shadows actually have a bluish tint to them (this is because the sky is blue, and the light coming from it blues up all the shadows on the ground).
All the shadows in this picture of mine are all the same dark blue color:
I’ve heard that whatever color the light source is, the shadows are going to be whatever color is on the opposite side of that color on the color wheel. So, since the Sun is yellow, the shadows are dark blue, since dark blue is on the opposite side of yellow. If the light was blue, does that mean the shadows would be dark yellow-tinted?
...mmmaybe?
I've also heard shadows on skin are often a little bit reddish. This is because the light is getting a bit into the precious, precious blood underneath your skin (put your fingers together and hold them up to the Sun and you'll see it). The scientific term for this is "subsurface scattering". The term I use for it is "precious, precious blood".
Different Methods of Shading
The method you use for shading determines what the shadows will look like. There's about three well-known methods of shading - one kind of "hard" shading and two kinds of "soft" shading.
“Cel shading” is the hard shading. It’s drawing the shadows and lights right on with the pencil tool, leaving a hard line between them. It makes the drawing look cartoony – in fact, it’s named after cartoon “cels”, which are individual frames of animation (it's short for "celluloid", which is what they used to be made of).
The first kind of soft shading is using an airbrush to draw on the shadow and lights. This leaves a soft edge between the two and allows for a more gradual transition.
The second kind of soft shading involves blending. Basically, just like the cel shading, you start with drawing the shadows and lights on with the pencil tool. Then you take the watercolor brush tool, and you scrape it along the edges of the shadows and lights until it looks like it’s softened up. It’s a little finicky, but it affords more control over the shape of the edges than the airbrush method.
If you’re using Paint Tool SAI 2, there is a fourth option using the blur tool. Like before, we cel shade the shadow on – and then right on the line, we add a color that’s somewhere between the base color and the shadow color. Then we take the blur tool and we rub it all over this line until it looks like it’s blending into the base color.
Shadows on the Ground
When we think of shadows, we usually think of the one that stretches out behind us on a sunny day. Artists call these "cast shadows", but I keep forgetting this. I often call them "tail shadows", because they're like tails jutting out beneath us.
Here’s a very very quick, very very bad drawing of what I hope looks enough like a skyscraper. The Sun is up and over on the right-hand side. So, where’s the shadow going to be?
Well, shadows, like everything in a scene, are all part of the perspective. All the lines in a drawing are pointing towards a “vanishing point” somewhere on the horizon line.
(My lines are a little wonky and they don’t really line up with a proper horizon line. Which is fine – if you work backwards by drawing a wonky sketch first, then finding roughly where most of the lines are pointing to, you can use that as the vanishing point for a new, more refined sketch on top of the old one.)
The shadows also stretch towards a vanishing point – but it’s not the same vanishing point as the rest of the scene. They stretch towards the part of the horizon that’s directly underneath the Sun. So, draw a straight line down from the Sun and you’ll find this “shadow vanishing point”.
So, where is our shadow going to be? Well, try drawing a line from the shadow vanishing point through all the visible corners on the bottom of the skyscraper.
You can really see how wonky my skyscraper is… but you can also see that the shadow is going to stretch out from where these lines come shooting off from the bottom of the skyscraper.
But how long will our shadow be? We know where it will start, but where will it end? We can figure this out by drawing some more lines – but this time, they’re going to be drawn from the Sun itself, and they’re going to go through the top corners of the skyscraper.
Where the top lines and the bottom lines meet – that’s the area where the shadow’s edges will be.
Well, this is a little awkward. My top and bottom lines don’t meet – they go right off the edge of the picture. In this case, I suppose we can just draw a shadow that also goes off the edge.
Let me make a smaller building instead. Don’t worry, I paid a bit more attention to perspective this time:
Same method as before: first we draw a line going down from the Sun to the horizon to find the shadow vanishing point…
...then we draw lines from the shadow vanish point to all the bottom corners of the building we can see…
...then we draw lines from the Sun to the top corners of the building we can see.
So now we have the points of our shadow. The shadow will start where the bottom lines come out the building, and end where these lines meet with the top lines coming out the Sun.
You can combine these tail-shadows with body-shadows (you know, the shadows on the body of the object) to create some cool effects. Here I added two multiply layers the same dark blue color - one at the back at a higher opacity, and one on the side at a lower opacity so it's less dark.
Bouncy Ambient Light
This optional segment is going to go into some specialist science-y stuff, so you can skip past it if you want. This isn't something I really use myself - I'm just introducing it here so you don't get thrown through a loop when another tutorial brings it up.
The thing about light is it doesn't really just shine on things and that's that. Photons (the little balls light is made of) actually bounce and spring around between things like a pinball machine.
The other thing about light is, in my view, that "color" and "light" are the same thing. Light is color and color is light. Light looks invisible to us, but it's actually every color at once. You can see this in rainbows - after it's been raining and there's lots of water in the sky, the Sun's light particles smash into the rain particles, and it causes the light to scatter into different colors.
For whatever reason (I don't know why), whenever light lands on an object, that object absorbs every color from the light - except for one, which it reflects back out. So, a red thing is red because it's basically eaten every color of light that's fallen on it, except for the red light, which it's spat out. Since the red light is the only survivor, it's the only color we see on that object.
Black is a little different, because it eats all the colors at once and doesn't spit any out. White is also different because it reflects all the light back without absorbing it (I guess it doesn't like the taste of color).
Why am I telling you this? Because there's a technique some artists do called "ambient" or "reflected" light that makes use of these facts.
Let's imagine a red, juicy apple lying on the green grass on a blue sunny day.
(I know it's dreadful, just bear with me here.)
The apple, we know, is red because it's eating the light spectrum and spitting out the red. The green grass is spitting out the green, and the sky is spitting out the blue.
But they're not just spitting it directly into our eyeballs, since as we said the light particles are pinballing everywhere. So they're also spitting it at each other.
That means the green grass beneath the apple is spitting a little of its green right into the apple's shadow. So, on a screen layer turned waaaay down to 25%, I have added a smidgen - just a touch - of yellow airbrush to the shadowy underside of the apple.
...alright, that's looks pretty awful. Maybe we shouldn't be combining shading styles like this. Let me see if it looks any better in hard cel-shaded style.
...a little bit... maybe?
Why yellow? Because yellow is right between red and green. When you do this "bounce light" between objects scrunched close together, you want to make it a color halfway between the one and the other. If I just made it so the bounce light was just the green of the ground, it'd look like this:
But it's not just the grass. The bright blue sky above is also getting in on the action. Another screen layer at 25%, this time on the very tops of the apple. The color is just the very same blue as the sky:
It's very very thin, but it's there at the edges. The sky isn't exactly super-close to the apple like the grass is, so I don't suppose the effect will be as intense.
It's very very thin, but it's there at the edges. The sky isn't exactly super-close to the apple like the grass is, so I don't suppose the effect will be as intense.
How does it look? I... have absolutely no idea. You've just seen the first time I've ever done this, and I've got nothing else to compare it to. I guess it's not... horrendously bad? I mean, sure, a big-shot digital artist like pikat or LavenderTowne would probably look at this and have a conniption, but for a mere mortal like myself... I'm just happy it still looks like an apple.
Shading in Nooks and Crannies
There's things that are in shadow because they're facing away from the light. There's things in shadow because something else is standing in front of them and blocking the light. And then there's things in shadow because the gap between them is so close together, no light can squeeze into it.
The proper science-y term for this is "ambient occlusion", but that's like three syllables too many, so I just call them "nook and cranny shadows*", because they fit into all the nooks and crannies light can't get to.
*which is also six syllables... but it's an easier thing to picture.
Say there's two circles bunched close up against each other. Right where they're touching, there's going to be a particularly dark streak of shadow.
Of course, the circles aren't really touching - if they were, there wouldn't even be a shadow. They're just so close together light isn't really able to squeeze through.You can see this in action with folds on clothes. Take this skirt here - there are little tube-shaped crevices between the big pleats that are blocking the light from getting in. These in-folded areas will be darker with shadow. You might also put a bit of shadow at the top where the skirt meets the belt. Since they're getting close to each other at an angle, it creates a sort of crevice at the point where they meet that light has a harder time getting into.
On a body, nook-and-cranny shadows show up in a few common places - underneath the chin, under the armpits, between the thighs, inside your belly button, etc. If two separate body parts - like the arm and the chest, for instance - are close enough to each other as to be nearly touching, there'll be a dark shadow on the skin between them.
Where to Put Shadows
But let's come to the main crux of the matter. The entire reason I made this. We know how shadows work. We know the different types. Now it's time to put pen to paper and answer the most important question - where do you actually put the shadows on your character?
...I've got no freaking idea.
And you know what's worse? I don't think anyone else knows either.
I've searched high and low, YouTube video after YouTube video, and the best advice anyone's got runs like this:
- Determine where the light source is in your scene
- Decide the shading style you'll use
- Something something something
- Boom, you got shadows!
The only piece of advice that stuck with me was this. I don’t remember where I heard it from – I want to say it was the Etherington Brothers or someone else they were showcasing – but the basic idea is: try and imagine yourself as the Sun. Try and picture in your mind what the scene looks like from the perspective of the Sun (or whatever other light source) looking down at your character. All the bits that the Sun can’t see are the bits that are going to be in shadow.
But other than this, I'm at a loss. It's easy enough to shade something like a sphere or a cylinder because that's just a basic shape. It’s not like you can just mentally reduce the whole character down to basic shapes and shade them in light of this… can you?
So, with nothing else for it, I decided to fall back on the most reliable method I have - THEFT.
Over the past month, I've been cribbing drawings of their characters artists have done and dissecting them to see where they've been drawing their shadows. And, at least with artists whose styles are similar to mine, I've noticed a few similarities.
All other things being equal, the pattern I've noticed looks something like this:
As you can see, usually the characters are facing the direction of the Sun. The red areas represent shadow, and the blue areas represent highlights.
There's a small shadow curving up from their jaw to their cheek, and the neck is mostly in shadow, as are the tops of the shoulders. The sides of the arms and legs away from the light are near-half covered with shadow.
The highlights, meanwhile, are a lot thinner than the shadows, and come down the sides of the character facing most directly towards the Sun: the top of the head, the leftmost sides of their arms and legs, the left side of their torso, etc.
If we moved the Sun over to the right, the result might look like this:
We've essentially swapped the shadows and highlights around. Now the highlights snake down the far ends of the character's right-hand side (from our perspective), while the shadows take up more space on the left. The neck is still completely covered, and so is most of the character's right arm, which is a little behind the torso and near-completely blocked from the Sun, save for a little sliver of highlight at the inner edge.
This isn't an exact science, this is just a rough pattern I've noticed for characters drawn by artists whose styles I steal take inspiration from. If you have any artists you like, take a look at their character drawings and see where it is they put the shadows. Maybe take out a red marker and draw over the shadows to point out where they are. Where do you think the light source would be in light of where the shadows are?
Try and remember the basic 3D shapes and how they'd be shaded. If the character has a big ol' beer gut, that'd basically be a sphere and would be shaded as such. Something like a wide-brimmed hat might also kind of look like a flat sphere (wonder if there's a name for that?) and might be similarly-shaded with an arc of shadow over on one side. And arms are usually two cylinders connected to each other by a sphere.
With all this in mind, I've re-drawn the character from the start of this tutorial and applied shading with this model as a guide:
So far I've only been focusing on drawing in a cartoon style, because that's really all I know of art. If you're the type to draw your characters with noses, you'll often find it creates a weird sort-of triangular patch of light right on the cheekbone on the side of the face away from the Sun.
This is called the Rembrandt triangle, after the artist who used this type of shading a lot. It's formed by three shadows connecting with each other: the shadow on the side of the face away from the Sun, the shadow formed by the brow, which is a lot bigger on the dark side of the face, and the shadow formed by the nose, which creates this big sort of chunk going from the nose to the cheek.
This is all I know about shading as it stands right now. Hopefully it'll be enough for at least a giant-headed, bug-eyed noseless abomination character style like mine.
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