Teach Yourself Adobe Photoshop CS2.pdf - Online Public Access ...

This document was created by an unregistered ChmMagic, please go to http://www.bisenter.com to register it. ThanksWorking with Multiple LayersYou have seen how to create, move, and remove layers, but the hour still hasn't really addressed the question of what they're good for.You will use layers in many situations. Whenever you are combining two or more images (in Photoshop terms, compositing), the elementsyou paste or drag in from another document over the background image are added on separate layers. You can use the Layers palette tocontrol precisely how these elements are combined. You can control the opacity of objects you paste onto a layer or paint that you applyto it. (The layer itself is transparent, even if you set the paint on it to 100% opacity.) You can also control the blending modes that affecthow one layer appears on top of another, just as you can when painting over an image or background.OpacityThe Opacity slider at the top of the Layers palette controls the opacity of the active layer. You used it briefly earlier to change the opacity ofthe bacon. Make the slider appear by clicking the triangle to the right of the percentage window. It can be adjusted from 0%100% bydragging the slider. If you'd rather not access the slider, enter a value by typing 0 for 100%, 1 for 10%, 2 for 20%, and so on. If you desiremore precise control, simply type the digits of the measurement you desire (57, for instance) in quick succession. This trick works with anytool that doesn't have its own Opacity settingwith tools that do have Opacity settings, use the keyboard to adjust the setting for the toolrather than the layer.Let's practice some more with the Opacity slider. You should still have the sandwich open on your screen. Make the tomato layer activeand drag the Opacity slider (by clicking and holding down on the arrow button to make it appear) to about 75%. Can you still see thetomato? Yes, but it's sliced very thin. Drag the slider down to 10% and then to 0%. Then move it back to 100% again. Pretty cool, huh?The Opacity slider has no effect on the Background layer. It always remains at 100% opacity. There is, however, a way around this. Thereis a difference between the background of your image and what Photoshop sees as the background to your layers.You can create a document with a transparent background by choosing File New. For the contents, choose Transparent, as shownin Figure 11.12. When the canvas opens, you'll see a checkerboard pattern as a placeholder, indicating that there's nothing on the layer. Ifyou look at the Layers palette, you'll notice that the blank page is called Layer 1 and not Background. That's to help you remember thatyou can change the opacity. Anything you paint on that layer will have a transparent background. Anything you copy from another sourceand paste in will go on a new layer that can also be made transparent.Figure 11.12. Making a transparent background.