Advanced Layer Features

Advanced Layer Features

The Group with Previous command under the Layer menu allows you to use one layer as a mask for other layers. When you define a clipping group, the lowest layer in the group becomes the mask for the other layers in the group. Since layer clipping groups are a more advanced feature, I am not going to discuss them in great detail here. However, I will show you some simple examples of where you might find them useful. If you'd like to explore them further, see pages 275-276 in the Photoshop 5.0 User Guide, or pages 218-219 in the Photoshop 6.0 User Guide.

One useful application for grouping layers is when you want to fill text with a photo or fill. Sure, you can make a selection from the text and paste into it, but then the text would not be editable. For this exercise, I've created a file with a white background, a rainbow filled gradient layer, a (hidden) texture layer, and text layer. Save this file to your hard disk and open it in Photoshop. We're going to fill the text with a gradient and then apply a texture. (When you open the file in Photoshop 6, you may get a message that some layers need to be updated. Click Update if you see this dialog box.)

Since the bottommost layer is always the clipping layer, first you will need to move the text layer below the gradient and texture layers.

1. Use the layers palette to drag the layers into this order from top to bottom:
   • Texture
   • Rainbow
   • Photoshop
   • Background
2. Next make the Rainbow Gradient layer active, and choose Layer > Group with Previous or Ctrl-G/Command-G.
3. The text is now filled with a gradient.
4. Make the Texture layer active and visible by clicking on the layer name.
5. Group this layer by hitting Ctrl-G/Command-G. (Another way of grouping the layer is to Alt/Option click on the border between two layers in the layers palette.)
6. At this point the texture is blocking out the gradient fill. We'll use layer blending modes to apply the texture to the rainbow fill. Change the blend mode of the Texture layer to Luminosity.

Now you have textured, colored text that remains editable!

Are you beginning to see the power of Photoshop's layers? Well, hold on to your mouse, because this is only the beginning!

Layer Masks
Layer masks are very much like quick mask selections or alpha channels, but they are linked only to a single layer. They can be edited and are saved with your document when you save in the native Photoshop file format. Layer masks can be started from scratch, or applied from an existing selection. Layer masks are especially powerful because they allow you apply transparency to a layer without permanently destroying the pixels in the layer. As long as the layer mask is linked to the layer, portions of the masked layer can be hidden and revealed without harming the original pixels. Layer masks are ideal for creating composite images and montages.

Adjustment Layers
Adjustment layers are special layers that are used to make adjustments to the underlying layers. Most of the items under the Image Adjust menu can also be applied by using an adjustment layer. Using an adjustment layer has a distinct advantage, because... well, because it's adjustable! In other words, if you apply a Hue/Saturation adjustment to an image, and then later decide the change is too drastic, you can double click on the adjustment layer and revise the settings. In addition, adjustment layers have built-in layer masks, so you can erase the adjustment from selected areas by painting on the adjustment layer with black. Painting on the adjustment layer with shades of gray allows you to selectively fade the adjustment.

Layer Effects
Layer effects are special effects that can be applied to a layer. The great thing about layer effects is that they are fully editable and dynamic. You can modify the contents of a layer and the layer effects automatically change as the layer contents change. You can also adjust various aspects of the layer effects. In Photoshop 5, the layer effects include Drop Shadow, Inner Shadow, Outer Glow, Inner Glow, Bevel & Emboss, and Color Fill. All of these effects could be created in Photoshop, prior to the addition of the layer effects feature in Photoshop 5, however, it required many layers and steps, and if you changed the contents of the layer the effect would have to be recreated from scratch! Learn more about layer effects in this overview written for Photoshop 5. Photoshop 6 users will find it useful, too, but the dialog boxes will look a bit different.

Photoshop 6 Fill Layers
Fill layers are unique to Photoshop 6. A fill layer can contain a solid color, gradient, or pattern. When you designate a layer as a fill layer, the fill can be changed very easily by clicking its icon on the layers palette. Fill layers also have layer masks attached, so portions of the fill layer can be nondestructively erased, just by painting on the layer mask.

Photoshop 6 Shape Layers
Another type of layer new to Photoshop 6 is a shape layer. Shape Layers are essentially fill layers with vector clipping masks (as opposed to raster layer masks). The contents of shape layers can be changed on the fly, just like Fill layers. The clipping mask is an actual vector shape that can be manipulated through the direct selection tool and, unlike a raster layer mask, vector shape masks will always have crisp, sharp edges.

Note: When advanced TIFF options are enabled in Photoshop 6.0, layer masks and adjustment layers are also preserved for TIFF files. However, layer effects, shape layers, and fill layers are not preserved in TIFF files.

We'll practice using layer masks, layer effects, and adjustment layers as we progress further in the course, but first we need to cover more of the basic tools. We'll pick up next week with working with text.