In this lesson, I’ll explain how you can make your color illustrations monochrome (black-and-white only) without adding revisions so that you can return the image to its original state at any time.

 

I’ll turn the below color illustration on the left into the manga-like black-and-white illustration on the right with lines and screentones.

 

As you can see in the below image, my lines and colors are spread across multiple layers.

 

To turn the image black-and-white, I will mostly be using the [Layer Property] palette.

If the [Layer Property] palette is not displayed on the screen, you can display it by opening the [Window] menu and clicking [Layer Property].

 

For details on how to use the Layer Property palette, refer to the following article.

 

[1] Making the line art black-and-white

In this example, the line art on this color illustration was drawn with the [Pencil] tool in grey.

First, I go to the [Layer Property] palette and change the [Expression color] to Monochrome.

 

(1) I select the layer I want to edit on the Layer palette. In this example, I’m changing the “face” layer. I’ll change all the layers in the same way.

 

(2) On the [Layer Property] palette, I select the [Expression color] setting, and choose [Monochrome] from the drop-down menu.

 

(3) I changed the “face” layer to monochrome. However, in this example, parts of the ear and mouth are missing, and the lines aren’t converted very well if I use the default settings.

Note: To make it easier to understand, all lines that aren’t on the “face” layer are shown in blue.

 

(4) So, I adjust the settings for [Monochrome] in the [Layer Property] palette. By adjusting the [Color threshold] and [Alpha threshold], I can change how the lines are converted.

 

(5) In this example, the lines are drawn in gray, so changing [Color threshold] doesn’t have any effect. However, when converting the skin tone or the light blue lines on the white shirt, changing the [Color threshold] will have an effect on the converted output. Here, I lower the value of the [Alpha threshold] to convert the lines cleanly.

 

(6) I use the same method on all the other layers to make them black-and-white, shown in the image on the right.

 

Hint:

If you have a lot of line art layers, it can be time-consuming to change the expression color one by one. Instead, try duplicating all the line art layers and merging them into one, then changing the expression color of the merged layer to [Monochrome].

Once you’ve changed the expression color of the duplicated layer, you can hide the original layers.

 

[2] Changing layers to screentone

To make the non-line art layers black-and-white, select the raster layer or folder in the [Layer] palette, then go to the [Layer Property] palette and turn on [Tone]. It’s time-consuming to change each layer to [Tone] one by one, so I select the layer folder for all the colors and apply [Tone] to change them all at once.

Note: You can apply the [Tone] effect to layer folders as well as layers.

 

When we look at the image zoomed-out, it looks like grayscale when screentones are applied. However, if we zoom in, we can see that it is a black-and-white image with black dots.

 

[3] Adjusting the darkness of screentones

If we simply apply the [Tone] effect, the screentones lightly cover the entire face where it was colored on the original, making the skin look more tanned.

 

Some parts are darker than intended in the color image, while other parts are lighter.

We can adjust the darkness of the screentones by changing the [Tone] > [Posterization] setting, the [Layer color] setting, and [Opacity].

 

 

 

■A. Adjusting the hair with [Posterization]

 

First, let’s adjust the hair.

In the example, the hair looks quite flat and gray if I only apply the [Tone] effect. There are no white highlights or black fill. Using the [Tone] > [Posterization] setting, I adjust it to look like this.

 

(1) First, I select the “hair” layer folder inside the “painting” layer folder, and apply the [Tone] effect. The [Tone] effect is applied to the entire “painting” folder, but the settings of the embedded folder “hair” take precedence.

 

(2) Next, I check the box for [Posterization] to turn it on, and adjust the settings while looking at the image shown on the canvas. In my example, it looks like this when I’ve finished.

 

 

 

■B: Adjusting the skin using [Layer color] and [Opacity]

 

Next, let’s adjust the skin.

If I adjust this using [Posterization] as with the hair, the detailed shading of the skin gets flattened and makes the image look less skilled. Instead, I will adjust it using [Layer color].

 

(1) I select the base color layer for the skin, which is painted in a pale color, then go to the [Layer Property] palette and apply [Layer color]. Then, I change both the [Layer color] and the [Sub color] to white.

 

(2) By doing this, the base layer for the skin is now shown as white. Because it’s white, even when screentones are applied, the light gray color doesn’t appear.

 

(3) Because the base layer has been made white, the contrast with the shadows is a bit too strong, so I lower the opacity of the shadow layers. Here, the opacity of the shadows layers has been lowered to 30%.

 

I use the methods in A and B to adjust the rest of the layers.

 

[4] Extracting the lines from the background

In this example, I didn’t draw any lines for the background but painted it only with color.

With this kind of background, when you apply the [Tone] effect, screentones are applied over the entire image. As a result, the background becomes indistinct and it is hard to see where the girl is sitting.

 

By going to [Layer Property] > [Extract line], I can automatically create lines from the background like the below image.

 

However, I cannot apply [Extract line] to a folder, so before turning this effect on, I merge the layers where the background was painted separately.

 

Also, when [Extract line] is turned on, the parts of the layer where lines cannot be extracted will turn white, as in the below example. Make sure you make a separate layer for the background and the background lines.

 

(1) First, I merge and duplicate the background layers, and make a layer for the background lines.

I select the folder containing all my background layers, then right click and select [Convert Layer] from the pop-up menu.

When the [Convert Layer] dialog box is displayed, I check the option called [Keep original layer] and click OK.

 

(2) When the option [Keep original layer] is turned on, the “background” layer folder is kept, and a new layer “background copy” is created inside the layer folder.

 

 

(3) I move the “background copy” layer directly above the “background” layer folder and set the blending mode to [Multiply]. When set to [Multiply], the white parts become transparent, so it’s a useful mode for only showing the lines made with [Extract line].

 

(4) Finally, I use [Extract line] on the merged “background copy” layer and adjust the results. In this example, I adjusted a few of the values in the settings.

 

Now I’ve finished making the image black-and-white.

 

Using the [Tone] > [Posterization] setting, I can reduce the settings to create an image without any mid-tones, made of only solid black and white.

 

With this method, you can easily return black-and-white images back to color, and adjust the settings after you change the image. Have fun exploring this technique!