What are layers? What are they for?

Layers are like sheets of clear acetate that can be stacked on top of one another to form a single, complex image.

They can be used for two purposes:

1. To move various parts of a complex image around easily with respect to each other
2. To apply special effects to individual parts of a complex image, such as transparency, shadows, glows, and blends.

Here's an illustration of layers and how they work. On the left is a graphic in which the layers have been "separated" to make them easy to see. On the right is the Layers palette, used to identify and control the layers.

Let's start at the top and look at each layer...

• The uppermost layer in this example is named Frame 3. Originally, this layer just had a number, but you can give names to layers to make them easier to identify in the list. "Frame 3" was given to the layer because it contains the blue quadrilateral frame surrounding the words "INP Student.
• INP Student layer is below Frame 3. Photoshop automatically gave it that name because it is a text layer (notice the large T icon in the Layers palette), and the text is used as the layer's name. The effect called "Drop Shadow" has been applied to the layer, giving the letters a 3-D effect and making them easier to read against both light and dark backgrounds.
• The next layer down is Frame 1. It contains the red frame around the portrait. Notice in the left-hand column of the Layers palette: the color of this and the next layer is pink. By default, all layers in the palette are grey; layers can be colored to help identify groups of layers. In this illustration, layers in the palette were given colors similar to the frames in the graphic to help link them visually.
• Portrait is the layer with the photo of an INP student.
• Frame 2 layer contains the green frame.
• Landscape contains the photo of WCC's campus.

  Having looked at some aspects of layers in Photoshop, let's get some hands-on experience using them.

Getting started

Open an image to work with: the cropped version of your photograph from exercise D13h. (If you don't have that available, use any picture of a person or animal.)

Have Photoshop create layers for you

Photoshop automatically creates new layers when you do certain things. Try this to see two such things:

1. Make sure the Layers palette is visible. If you don't see it, use the Window menu and select Show Layers.
2. How many layers do you see? What is/are it/they called?
3. Use the text tool to put your name on your picture. (If you're using some other photo, put an appropriate name on it.) Use a font that's large enough to read, but not so large that it covers the face. Make the color and weight fairly easy to see against the background.
4. Check the Layers palette again. How many layers are there now? What is the new one called?
5. Copy this WCC logo from this Web page:  Paste it into your image in Photoshop
6. Take another look at the Layers palette... Has it added another layers? How can you identify it?
7. Save the file on your Zip disk.

Create layers yourself

You've see that Photoshop creates new layers for you when you use the text tool and when you paste one image into another. You can also create layers for yourself. It's simple!

1. In the Layers palette, click on the new-layer icon at the lower edge.
2. Check to see where your new layer is located relative to the others.
3. Use one of the fill tools to fill the entire layer with a color. Strong suggestion: choose interesting foreground and background colors, and use a gradient fill.
4. What does this do to the other layers in the image? If it covered them up, don't panic! We'll take care of it...
5. Save the file again.

Make layers visible or invisible

To the left of each layer in the Layers palette is a eye-icon. Clicking on this lets you selectively make individual layers visible or invisible.

1. Click the eye-icon on the layer with the color fill. What difference does it make?
2. Click the eye-icon of each layer, until they are all gone.
3. Try clicking to make each layer visible by itself.
4. Finally, restore all the layers to being visible.
5. Don't forget to save your file!

Change the transparency of layers

In the upper right-hand corner of the Layers palette is the Opacity control. Opacity and transparency are opposites: 75% opaque is 25% transparent.

1. Click on the color fill layer to make sure you're dealing with it.
2. Adjust the opacity to about 30%. What effect does this have on the image?
3. Click on the WCC icon layer. Adjust its opacity downward. You decide what level works best.
4. Did yo remember to save your file?

Adding layer effects

There are a wide variety of effects, in addition to transparency, that can be added to a layer. We'll try some of the simple (but fun!) text effects here:

1. Double-click the layer-name of the layer that has your name (the text layer). This brings up a dialog box, giving you many options.
2. Experiment with layer effects. Be sure to include drop shadow, inner shadow, bevel, and emboss. Which makes the writing easiest to read? Which adds "coolness" to the writing? (Hint: A large, plain font, like Arial Black, shows the effects the best.)
3. You don't need to be reminded to save your file, do you?

Moving layers up and down

Moving layers allows you to make subtle (or extreme!) changes in the interaction between layers...

1. Point to the color fill layer. Drag it to the bottom of the list of layers. What effect does this have?
2. Move the color fill layer back to the top.
3. Move the text layer to the top. What effect does that have?
4. Find the best position for the layer with the WCC logo. Experiment with its opacity control.

Finishing up

When you are satisfied with the effect of the color fill, the WCC logo, and the writing together with your picture, save the file one more time. Then use the File menu's "Save for the Web" option and optimize the image as a JPEG. Email the JPEG version as an attachment to your instructor, but keep the Photoshop (PSD) file in case you need to make changes. You're done!

Audience: This is for people who are familiar with the basic tools of Adobe Photoshop and want to learn how to use layers.
Objectives: When you successfully complete this lesson, you will be able to...

1. Explain the concept and purpose of layers in an image
2. Determine which layer is active at any given time
3. Create a new, empty layer
4. Delete an unneeded layer
5. List the actions which cause Photoshop to create a new layer
6. Adjust the transparency of layers
7. Make layers visible and invisible
8. Move layers relative to one another
9. Add effects to layers, including drop shadows, glows, beveling and embossing

About this document...
Module D15h: This document is part of a modular instruction series in computer technology. For more information, see the overview or the list of modules in this series, D: DESKTOP PUBLISHING AND COMPUTER GRAPHICS. This document has been used in the following classes: INP 152.

Author: Laurence J. Krieg
Institution: Internet Professional Department, Washtenaw Community College
History: Original (as D15h): October  2001; This revision posted Monday, 31-Aug-2009 11:47:56 EDT
Copyright © 2001, Laurence J. Krieg, Washtenaw Community College

Instructors: You are welcome to point to this file in your Web-based materials.
Students: you may make a copy for your personal use.
All other uses: contact the author, Laurence J. Krieg for permission.