Often when a digital colourist scans a lineart image the scanned product isn’t a true black, and this can affect the overall final image quality. Occasionally too, the artist wants a final lineart image that doesn’t consist of black lines, but rather some other colour. This section will explain an easy method to making sure that you get what you want by using what are called channels in photoshop. The advantage of this method is that you end up with a lineart layer that consists only of the lineart with the rest of the layer remaining transparent and so open to manipulation.
Be sure to have cleaned up your image as best you can as this method will select every single smudge mark and glitch otherwise along with the rest of your picture. Clean up your image before beginning this method by adjusting the levels in the IMAGE – ADJUST menu until you have as clean a black and white image as possible.
Opening your image in photoshop, first make sure that the mode is in RGB mode (IMAGE – MODE – RGB) as you are going to need the colour channels. Select the blue channel and drag it down to the copy icon at the bottom of your channels dialogue box. It will be renamed ‘alpha 1’
Invert the colours of this new alpha channel (CTRL – i).
At this point you can switch back to the layers dialogue box and delete the original lineart layer as you won’t need it anymore. Create a new layer and then go to “Load Selection” (SELECT – LOAD SELECTION) and choose the alpha 1 channel option. This will fill the layer with the familiar ‘marching ants’ in photoshop.
Now fill the image with either black or the colour of your choice. (EDIT – FILL) In this case for demonstration purposes I have used a reddish-purple to show more clearly how I have been able to select the entire black areas of the original lineart.
Colouring the Image:
These stages will show you how to colour the shaded areas of the picture. Since I use essentially the same method for all the different sections of the picture, I have concentrated on the girl.
Step One is to create a new layer beneath the lineart layer. I now go and paint all the “Flats” of the picture. These are the broad block areas of colour and serve as the base over which everything else is painted. At this point I choose a mid-tone for my colours as I will add darker areas and highlights later. This process in itself can be quite time consuming, especially if there are elaborate backgrounds and the like, and within the comics industry people are employed to do only this stage.
Some people prefer to have each Flat colour on a separate layer but this is up to you. In this case because there is a distinctly separate background image I have used 4 separate flat layers consisting of the girl, the dead guy she’s standing on, the rocks and water, and the sewer outlet background. These block in the major areas of each component of the picture and will make it easier to paint the other sections without interfering with the girl in the foreground.
Step Two is to start painting in the darkest skin tones. To paint this layer I use a custom ‘200’ brush that I have created and just lightly airbrush it past the edges in a series of passes until it covers as much of the area that I needed. In other parts such as the main thigh in the foreground I was able to use a custom gradient of skin tones that I have created to save some time. Continue adding these dark tones to all of the skin sections.
I’ve spent quite some time working on custom colours for my skin tones and have them as custom swatches in my colour palette as well as the gradient tool. I have also created a series of custom brushes by taking the default ‘100’ brush setting and making two new ones at 200 and 300 settings on the diffusion level. I left all other settings the same. With these modifications I find I can do just about anything I need to when colouring various pictures.
Next is to paint in some faint diffuse muddy-purple shadows over the previous layer. Adding this purple layer really deepens the shadows and will make the other shades and highlights “pop” out even more. For this I used the 200 custom brush and barely touched the edges of the brush to the side of the leg to get a very diffuse shadow effect. I have also added a layer of very light skin tone to also make the lightest areas such as the foreground thigh area pop.
The final layer for the skin areas is to add the secondary light sources. Secondary light sources can be just about any colour you like as they indicate another light source of some kind. They are there to highlight the edge of the region and to give the picture a little extra ‘pizzazz’.
Having done all the skin tones it’s now time to begin the armour. In this instance I had to select each section of the armour individually with the lasso tool in turn and then used the gradient tool set to circular mode. The colours are a few shades lighter and darker than the chosen flats colour. I’m sure you can imagine that this took ages to do all the armour sections, and it did! The armour consumed the majority of the time taken to colour the entire picture.
In this screenshot I’ve completed all of the girl’s armour, skin tones, lips and hair. The hair has been highlighted by adding a section of a light tan and then used a small brush and the smudge tool. I then repeated this on another layer with an even lighter colour. Adding the very fine shadow on the piece of hair that goes over her face gives it even more depth. The lips have been shadowed with a dark layer of red and then highlighted with a dot of orange and smudged to fit. For an even brighter highlight on the lips you can also add a dot of white. As the armour is highly polished and reflective I have added very pale and diffuse green highlights to various sections and finally some flare points to add some “bling bling” to the armour.
Now it’s just a matter of repeating the same basic steps and ideas for the rest of the picture components. For this Cici picture once I finished the girl, I then flattened the layers beneath the lineart before beginning the same process on the background components. This made it easier to work on the background as I didn’t have to worry about interfering with the layers of the girl. It also kept the total number of layers down to manageable levels at any one time!
You may find some areas haven’t been fully selected by the lasso tool and in this case I use the smudge tool and a small airbrush setting to gently rub the colour into this spot. For very small areas (such as the armoured outfit Cici is wearing) I might use the small airbrush tool to paint in a spot colour or a small area and then use the smudge tool to push the colour into position. It all depends on the picture and the section you are doing for what choice of method you make at the time.
When I have done all the shading I usually do a final save of this file with all it’s many layers and then flatten all the colour layers beneath the lineart before doing a final cleanup on a close zoom for any stray edges or bleeds of colour and then save this as a separate file. This means if I make a mistake in producing the final image I have the master image to go back to. I then flatten the lineart and coloured layer together before adding a background if I need to, but which obviously wasn’t in this case.
Here's a link to the final finished image