It can often be the case that what separates good art from great art is a sense of depth to the image.  You can be the finest figure sketcher in the world, and have amazing ink work with glorious colour but if someone else comes along with all your skills and still manages to produce art that has a certain something extra, chances are they’re shading.  It adds a feeling of tangibility to the image, and also makes it look more natural.

This little fellow is inked and coloured but he has no depth (aww!)	Now he looks more three-dimensional, thanks to some simple shading. Image by jinxtigr of Tally Road (warning: adult content link)

The amount of time an artist spends on shading need not make the artwork unwieldly and draw out the creative process to the point where sitting down to produce the next episode is akin to pulling teeth.  Yes, shading can be a long-winded process but it doesn’t have to be.  There is a simple way to do it.

Seeing in three dimensions
The first stage in good shading is not shading at all, it’s visualisation.  When inking and colouring it can be easy to forget that you’re working on what is supposed to be a depiction of a three-dimensional space.  The image can become nothing more than a series of lines interspersed with splashes of colour and that’s fine as far as drawing and colouring are concerned, but if you try to shade an image when thinking of it as a two-dimensional shape, you’re going to run into problems.

Take a sphere, for example.  Seen in two-dimensional terms, a sphere is simply a circle.  Its surface is flat, and light will hit it at the same intensity at every point across its surface (assuming that the circle is directly facing the light, of course).  Not so with a sphere; some points will be closer to the light than others.  It will have light and dark patches.

Now let’s put a cube into the image, between the light and our circle/sphere.  A cube is nothing more than a collection of flat surfaces but, again, some of those surfaces will be closer to the light, some further away.  Some may not get any light at all, depending on the kind of light we are using (point lights, sunlight, etc.).

The cube would therefore be lightest on the surface facing the light; darkest on the surface facing away from the light; and shaded on the other surfaces to varying degrees based on their orientation toward the light.

But what will the circle/sphere look like now there’s a cube between it and the light?  Assuming the cube is oriented so it faces the light dead-on, it will be casting a square of shade behind it.  The area of this square will grow larger and larger the further away from the square we get, although the intensity of the shade will also fall off exponentially.  This is only really of note when looking at extreme distances however, so for now we will simply think of the circle/sphere being reasonably close behind the cube.

When looking at the circle, we will see a mostly uniform light level and a square patch of shade.  Fair enough, you might say.  On its own, this does not mean much (and the image to the left no doubt shows that it looks a bit stupid) but when the circle is a wall and the cube is your main character, suddenly you have something that enchances your comic: a realistic shadow.

Pick a light source
In any scene there will be a primary light source.  Chances are there are several: a streetlight and some car headlights; or maybe a desk lamp and moonlight streaming in through a window.  For every character or object in the scene, one of these will be its primary light source.  Identify that, and bear it in mind.

Once you know where the primary light source is, you can begin to imagine the shape of each object in the scene and how it interacts with everything else.  Like the cube and the sphere in the example above, light will hit the surface of the object in a certain way depending on its shape, and it will cast shadows on the other objects around it based on the direction of the light.  This is why it is important to think of the objects as three-dimensional.  If they were two-dimensional, the light would just hit everything at a uniform intensity; like it did our blue circle, above.

Creating a simple shading effect
Now we know the way our objects are going to be shaded, we need to discuss how to actually shade them.  It is important not to risk ruining the artwork produced so far when, inevitably, a slip of the pen happens; or we decide that actually we’d prefer the light to come from a different angle.  Shading should therefore be done on a separate layer to the inking and the colouring.  This will have the further advantage that we can use opacity levels to change the intensity of the shadows.

Create a new layer and set it to an initial opacity of 9%.  This will give a reasonably deep shadow when shading.  Now set your ink to black and, with the pencil or brush tool (whichever you prefer), draw a rough outline of the area to be shaded.  If it’s a large area, bucket fill can be used to fill it, or you may prefer to simply paint in the missing parts by hand.  Because the shading is on a separate layer, any mistakes can be erased without damaging the artwork underneath.

Once the shading is done, it’s time to look at where the light is most intense.  Areas catching the most light will be lighter in colour than areas catching less light.  These highlighed areas are the opposite of shadows and need a separate layer all to themselves.

Again, this gives the advantage of being able to correct mistakes without damaging the rest of the artwork but it also gives a nifty little feature whereby crossing a line of highlighting with a line of shading will not produce the original colour; so intermediate shading can be achieved without extra fiddling around.

Create a new layer and set it to an initial opacity of 12%.  This will give a reasonably highlighted area when using white ink.  As with the shading, simply outline the highlighted area and then either bucket fill or fill in the middle by hand, whichever you prefer.  If you’re wondering why this layer needs to be more opaque than the shading layer, it’s simply a matter of white being harder to see than black; so we need more of it to get the right effect.

Now your shading is complete, experiment with opacity levels to get the right level of shading and highlighting for your image.  Every artist will have their favourite default amount, so see what works for you.  For other effects, try using different colours for the shading and highlighting, rather than just black and white.  Lighter and darker shades of whatever colour your characters and objects are can give excellent results, for example.

Many webcomic artists swear by the premise that colour can make or break a comic.  When done well, colour can add an extra level to an otherwise flat and dull comic; perhaps even going to the extent of making readers take interest when they would otherwise have simply passed by.

But colouring can be a long and tedious process, especially with the anti-aliasing effect in Photoshop leaving a nasty border around anything that is block-filled without a perfectly straight edge.  So what can be done?

When inking comics in a program such as Photoshop, it is always a good idea to do the inking on an otherwise transparent layer.  This gives the advantage that the ink can be toyed with in many interesting ways, but it also gives a distinct advantage when it comes to colouring.  It’s true that colours can be bucket-filled directly onto the ink layer but doing this will lead to one of two results: either there’s a border around the colour; or the line work is eaten away by repeated clicks to get rid of the border.  Neither of these will make the comic look good, and will turn off readers by saying your comic is unprofessional.

Making a separate layer for the colouring is a good first step to avoiding both of these problems.  From here it’s possible to select areas (either using the lasso tool or magic wand) and bucket fill them with the required colour but doing this will still leave the anti-alias border that makes the colouring look amateur at best.  When choosing this route, be sure to then go around the bucket filled area with the brush or pencil tools and colour right up to the line work. Because the inking is on another layer, there is no need to worry about colouring over the lines; just keep the ink layer above the colouring layer and you’re set.

However, this method is still time-consuming.  On even a moderately complex three-panel comic, colouring with this method can take hours – often several times longer than it will have taken to do the inking.  Surely there must be a quicker method?  Thankfully, yes.

Another advantage of putting the inking on a layer to itself is that this layer can be duplicated.  Duplicating the ink layer and then repeatedly bucket-filling each section with the required colour has all the advantages that the bucket fill process gives you such as quick flooding of areas with colour and adds a brilliant extra feature: repeated clicking with the bucket fill tool will not affect your line work.

The duplicate layer will have a copy of the inking on it and it is true that two or three clicks with the bucket fill will eat into that copy of the lines, but that does not actually matter at this stage.  It is also true that when the line art is duplicated, it will look bolder than it did originally.  Don’t worry about that right now, it will be taken care of later.

The original ink is still on the original ink layer, so if the lines on the new layer are eaten away, who cares?  They’re not going to be seen anyway.  Fill to your heart’s content, but remember that Photoshop and similar programs will often flood areas of similar colour when the bucket fill is used multiple times; so some areas will still need to be coloured by hand.  The amount of time you’ll have saved more than makes up for this, however.

Once the colouring is complete, use the ‘colour select’ tool to select every instance of whatever colour you used for your inking, and delete it.  This removes the last vestiges of your copied line work from the colour layer (make sure you have the colour layer selected when you do this, or you risk losing your original inking!) and leaves the artwork free from the problem of embolding the ink.

The only downside with this final stage is that it can cause Photoshop to select dark colours as well as the duplicate line art.  This is an unfortunate consequence of the colour select tool and does mean some dark colours (mainly greys) will still have to be hand-coloured but, again, the speed advantage elsewhere means this process will still drastically reduce the amount of time you need to spend colouring.