Lesson 6

Layers

Take a look at the Layers palette (left). It's packed with lots of helpful shortcuts and functions. I've numbered the fourteen items visible in this image, though more icons appear when you start adding and manipulating layers.

1. Name of the layer. When you open an image, the layer that appears is automatically considered the background. Adding more layers stacks them on top of the background. The image that you see in the workspace window is the view from the top down, looking through all the layers as if they were sheets of plastic stacked on top of each other. If you only use one or two layers, you probably don't have to worry about what they are called in the palette. If you start editing images with multiple layers, though, you may want to rename each layer to describe the contents of the layer so that you can find it again easily. You can rename any layer (except the background) by double clicking on its name and typing the name you have chosen.

2. Layer thumbnail. This is a tiny picture showing the contents of the layer. The gray and white checkered pattern indicates that the layer is transparent, like a blank sheet of clear plastic.

3. "Link" box. The active layer, in addition to being highlighted in blue, will have a paintbrush in this box. For the non-active layers, if you click in this box, an icon of a chain will appear. This chain icon indicates that the layer is "linked" to the active layer. If you move the active layer, any linked layers move along with it. This is particularly helpful if you have an object in one layer and its shadow in another, for example, and you want to move both the object and the shadow together. You can "unlink" a linked layer by clicking on the chain, making it disappear.

4. Layer visibility icon. Turning a layer invisible can serve many purposes. The main reason to make a layer invisible is so that you can see the layer(s) beneath it, but you may also do so to exclude it from actions such as merging multiple layers. Clicking on the eye icon toggles the visibility of the layer.

5. Blending mode. This determines how each layer blends with the layer beneath it. In "Normal" mode, each layer is handled as if it were paint on a sheet of plastic. In other blending modes, the computer will blend the colors of the layer with the colors of the layer directly beneath it. This blending can have vastly different effects depending on which mode you select. This will be discussed in more detail later.

6. Lock. Locking various aspects of the layer prevents you from making unintentional changes. The first icon allows you to lock the transparent pixels. Thus, if you draw a shape on a layer and then lock the transparent pixels, you can later color on top of the shape and not worry about coloring "outside the lines." Any stray strokes you make on the transparent pixels will have no effect. The second icon locks all the pixels so that you will not accidentally paint anything once you have it the way you want it. The third icon locks the position so that you don't accidentally move the layer once you have it located where you want it. The fourth icon locks all of these aspects simultaneously.

7. Opacity. This determines how "see-through" the contents of the layer are. 100% opacity means that the layer is completely opaque, and anything painted on the layer will completely hide whatever is beneath it. Reducing the opacity allows the layer(s) under it to show through. Opacity affects everything in the entire layer.

8. Fill. This is similar to opacity, but it affects only items that are painted on the layer. It does not change the opacity of layer effects such as "Drop Shadow" or "Stroke" that may have been applied.

9. Layer Style. This is a shortcut icon that has the same effect as clicking on Layer → Layer Style. It allows you to give the objects on the layer special effects such as shadows and outlines or to emboss them in various ways. This will be discussed in greater detail later.

10. Add Layer Mask. This icon is a shortcut for clicking Layer → Add Layer Mask → Reveal All. Layer masks are used like stencils to protect the layer so that only part of what is on the layer shows through. It is like an painter putting masking tape on the canvas, so that when the masking tape is removed, that section of the canvas remains clean. Masks will be handled in a later lesson.

11. Create a new set. A "set" functions like a folder does, keeping the layers within it categorized together, separate from other layers. It is possible to apply the same thing, such as a mask, to all of the items in a set simultaneously.

12. Create new fill or adjustment layers. This icon is a shortcut for Layer → New Fill Layer and Layer → New Adjustment Layer. A fill layer is like blanketing the layer with an additional color or pattern; this is generally used in combination with masks. Adjustment layers are used to adjust the properties of a layer in much the same manner as the "Color Balance" and "Hue/Saturation" dialogue boxes, but because each adjustment has its own layer, the adjustment itself can be adjusted at any time.

13. Create a new layer. This icon is a shortcut for Layer → New → Layer. If you click on an already existing layer and drag it on top of this icon, it makes a copy of the layer.

14. Delete layer. This is a shortcut for Layer → Delete → Layer. If you drag a layer over the trash can, it deletes the layer.

This completes the overall explanation...but what does it really mean? Most of the layer options sound like gibberish without examples of what they can do, so let's start experimenting.

What I want to do for this lesson is take this simple bunny sketch and turn him into a more three dimensional computer graphic. First I scanned the bunny from my sketchbook at a resolution of 300 d.p.i. (The image itself is quite small, but it looks large on the screen because it is at a high resolution.) I am posting the original here so that you can download it for practice if you wish. The remaining images of the bunny-in-progress will all be compressed to save space.

The bunny image is automatically imported as the background. The first thing to do is to make nice, clean outlines. It is possible to use the Pen tool for this, but that is an advanced technique that will be handled in a later lesson. For now, use the Brush tool.

Click on the "create new layer" icon at the lower left of the Layers palette. This will make a new, transparent layer on top of the background. It will automatically be given the name Layer 1. Double click on this name and type in "Outline" so that you will be able to identify the contents of the layer quickly. Making certain that your foreground color is black, use the Brush tool to trace over the outline of the bunny. Use undo or the eraser as necessary to fix any mistakes. You can make the lines as thick as you like; thicker lines have a more cartoony appearance. Zoom in if you need to in order to see well enough to trace properly.

Since it is difficult to draw perfect circles, you may wish to use the Elliptical Marquee when doing the face. The key is to create a new layer first, then use the Elliptical Marquee with Fill and Stroke to make the head, eyes, and nose. That way you can move the individual parts around without disturbing the rest of the outline in order to position them properly. Once you have them where you want them, use the Eraser tool to erase the segments of the outline of the head that are hidden behind the ears.

Once you have the face drawn on its own layer, you will need to combine it with the layer beneath it. To merge the two layers together, click Layer → Merge Down. The keyboard shortcut for this is Ctrl + E. This puts the face on the same layer as the rest of the outline.

After you have finished the entire outline, click on the eye icon of the background to make it invisible. You should have an image that looks like the picture on the left. Check the image to make sure there are no gaps or errors in the line. If there are, use the Brush and Eraser to fix them.

If you only want to paint a simple, flat drawing, or a drawing that approximates the look of actual paint, you can do so quite easily with just one more layer for the color. That would not give you very much practice, however, so I'm going to make it vastly more complicated for you. (Can you feel the love? ^_~)

Click on the background layer, then click the "create a new set" icon. New layers and sets appear directly above the active layer. If you don't move to the background first, the newly created set will appear above the outline, but we want the outline to stay on top. You can always move layers around, of course, but that would be inefficient. It's better to create it where you want it in the first place.

Double click on the set name and call it "Heart." Create a new set and name it "Arms." Repeat three more times, making sets called "Body," "Head," and "Ears." Your Layers palette should look like the picture on the left. (Again, this isn't strictly necessary, but you should know how to do it in case you ever need to in the future.)

With the Ears set highlighted as active, create a new layer. The layer will appear inside the folder (directly beneath the Ears folder icon). The thumbnail for this layer is indented to show that it is contained inside the set. Rename this layer something easy to remember. I called it "Ear base color." Select a light pink that you like as the foreground color and use it to paint the pink part of the ear. For the large ear, you can surround a large portion of the ear space with the Lasso and use Fill to save some time. You may want to make the background invisible again so you can make sure you are coloring correctly.

After you have finished the base color for the ears, repeat this process in each of the folders, working your way downward. For the rest of the body parts, you can use the Magic Wand as a shortcut. Click on the Outline layer to make it active, then tap the Magic Wand inside the relevant body part. Use Select → Modify → Expand to expand the selection by 2 pixels. Once that is done, click on the appropriate body part base color layer to activate that layer and use Edit → Fill to fill the layer with an approprate color. I used white for the bunny body parts and dark pink for the heart.

The series of pictures below illustrates this process.

When you have finished, zoom in and check the corners. The Magic Wand tool often leaves sharp corners unselected, as shown by the green circles in the picture (left). If this happens, use the Brush to fill in the gaps.

Now it's time to make the bunny look more three-dimensional by painting in the shadows. It's possible to use layer effects such as Emboss to make the bunny appear three-dimensional, but that will be handled in a later lesson. For now, you should know how to use layers to paint shadows on the image.

The trick to painting shadows is knowing where the light is coming from in the image. For this example, I'm going to decide arbitrarily that the light is coming from the upper left, as depicted by the yellow arrows in the picture (right). Anywhere the light falls will be bright. Wherever the light doesn't reach, illustrated by the blue arrows, will be left in shadow. In a simple image like this bunny, you don't have to worry too much about being an artist, just paint the shadows on the "underside" of the curves of the body parts or wherever one part shades another.

Select a light gray color for the foreground and choose a feathered brush tip for the Brush tool. Click on the layer called "Head base color" and from there create a new layer. Name this "Head shadow 1." Paint the shadows of the head on this layer. If the shadow that you paint doesn't look soft enough, you can use the Blur tool to soften it. Leaving the shadows with sharp, distinct edges makes the picture look more cartoony, whereas making the shadow edges very soft and blurry makes it CG-ish. I happen to like the soft, well-blended look, but you can do whatever suits your personal style.

If you ARE an artist--or want to feel like one!--you may want to try using the Brush menu to reduce the flow of paint to 40% or lower. This makes each individual stroke fainter, but wherever you overlap strokes, the overlapped area will be darker, just like when drawing with watercolors, markers, pencils, and other physical media. You can even choose a tip for your Brush that has a texture added to it that approximates the texture of chalk or a real paintbrush.

In this picture (left), I tinted the shadows pink so that you can see them clearly. Follow the same process to draw shadows for the rest of the body parts and the heart. Instead of gray, choose darker pink for the heart shadow. (Don't do the pink part of the ears...I'll handle those differently below.)

If you're not happy with the shadow color after you've painted it, you can always change the color of that particular shadow layer by tinkering with the color balance and hue/saturation. This is the benefit of painting the shadow on an entirely separate layer. You can also change the color by going to Image → Adjustments → Replace Color. This brings up the "Replace Color" dialogue box (right). This dialogue box allows you to select a color in a similar fashion to the Color Range function and use the sliders to adjust the selected color to your satisfaction.

Another adjustment you can make, if you think the shadows are too dark, is to reduce the opacity of the shadow layers. This makes them appear fainter, as the layer beneath them shows through. The pictures below illustrate the effect of changing the layer opacity of the heart shadow.

Opacity: 100%

Opacity: 75%

Once you have finished adding the first layer of shadows, choose a darker shade of the same shadow color and add a second layer of shadows. This time, click on the "shadow 1" layer, then create the new layer directly above it. Name this the "shadow 2" layer. Next, click Layer → Group with Previous. The keyboard shortcut for this command is Ctrl + G. When you group a layer with the previous layer, it automatically locks the pixels so that you cannot paint on any place that is transparent on the previous layer. This means that when you paint the second layer of shadows, you don't have to worry that you will color "outside the lines." You will only be able to paint over pixels that you painted in the "shadow 1" layer. The grouped layer thumbnail will be indented, with an arrow pointing down to the thumbnail of the layer beneath it. The picture (right) shows what your Layers palette should look like when you do this.

Paint the second layer of shadows near the edge of each body part. This second layer should be significantly smaller than the first layer so that it adds a sense of depth. Don't forget to make judicious use of the Blur tool to blend the shadows.

When you're finished with the second layer of shadows, it should look something like the picture (left). I tinted the second layer of bunny body shadows slightly pink to give the impression of light reflecting off the heart.

The bunny body is mostly white, so it doesn't really need highlights. The heart, however, could use some highlights on the upper rounded parts. On top of the "Heart shadow 2" layer, create a new layer and name it "Heart highlight." Choose a very light pink for the foreground color and a large, fuzzy brush tip for the Brush tool. You may even want to click the airbrush icon to make use of that function. Dab some round highlights where the light would hit the tip of the heart.

The pictures below show where to add the highlights.

Before

After

Now it's time to do the pink part of the ears. For this, I want to use the Gradient tool. The Gradient tool allows you to paint a smooth gradient from one color to another.

First, activate the "Ear base color" layer and create a new layer above it. Call this new layer "Ear shadows" and group it with the base color layer. This way the color won't spill outside the ear. Choose for the foreground a dark pink color that you want for the darkest part of the ear shadow.

Next, click on the Gradient tool icon in the toolbar. Take a look at the menu at the top of the screen (picture below). The most important options are the first two numbered items.

The first option lets you choose what kind of gradient you want. If you don't like any of the options, you can create your own by right-clicking on one of the gradient style icons and manipulating the colors and color spacing manually. You can then save your new gradient style to use later. This time, however, select the style indicated by the white arrow. This makes a gradient that fades from the foreground color to transparency.

The second option allows you to select the shape of the gradient. This time, select the very first icon. This makes the gradient proceed in a straight line.

Now you're ready to color the ear. Select the large ear section (loosely) with the Lasso so that the smaller ear section isn't affected. Click and drag to apply the Gradient tool approximately as indicated in the pictures (below). You can alter the appearance of the resulting gradient by changing the start and end points. This should apply a gradual shadow to the ear.

Before

During

After

Repeat this process for the other ear.

Ta dah! You have now converted a simple sketch into a cute computer graphic. The starting and ending points are shown below, along with an image of the bunny with the outline made invisible so that you can see just the effect of the paint.

Start

Finish

No Outline

Homework