Lynch covers everything from layer types, work flows, blending methods and channels. Each tutorial goes into great detail on how to achieve your given task and also explains why particular tools are used and how. The only real problem is that all this detail tends to leave the expert user wanting to skip through the book.
Beginners (and even a few intermediate) Photoshop users, as well as people new to pixel-level creativity software, general image editing and photo editing deserve an explanation of layers. For the uninitiated then, here's an explanation of layers from Virtual Training Help Center: http://iit.bloomu.edu/vthc/Photoshop/Basics/layers.htm "Layers are like transparencies stacked one on top of one another." Each layer can contain a different image, effect or modification which can stand out from, enhance or blend in with the contents of all the layers above and below it. When the layers are stacked, they appear as a single image. Individual layers in a Photoshop image can be turned on or off, allowing images to be saved in various different states. Parts of one layer can be used to hide or reveal parts of another layer. The list of functional and creative possibilities for layers goes on and on, and remains one of several important reasons that Photoshop, relatively early in its existence, garnered such widespread use by graphic artists and photographers around the world.
Beginners still not clear? Here's another explanation, this one from photoshopcafe.com: "A layer is simply one image stacked on top of another. Imagine I have a piece of paper and I paint it red. Then I take a piece of clear cellophane and paint a yellow circle, and lay it over the paper. Now I take another piece of cellophane and paint some blue type and lay that on top of the yellow circle. I now have a background (red) and 2 layers (yellow and blue)."
The Photoshop Roadmap and FreeTimeFoto explain layers this way: "Photoshop Layers are like stacks of images printed on acetate. An area that contains no color can be revealed to see the layer underneath it. That's called a transparency area. One Photoshop image can contain one or more layers. A Background Layer is a special layer with no transparency area and is common to other file formats that don't support layers (JPEG, BMP, etc.). When you open those file formats in Photoshop you will have only a Background Layer. One image file can contain only one Background Layer. In Photoshop, Background Layer can not be edited. A Type Layer is a special layer that can contain only text. It can be created automatically when you use the Photoshop Type Tool to type in any texts."
This description is from Jack Arraich's Photoshop Elements Tips: "Aside from the minor attraction of being able to keep your image organized by putting each element on its own separate labeled layer, the overwhelming advantage of layers is that they allow you to segregate your edits."
The Adobe Photoshop Layers Book uses a series of creative examples to expand the basic definitions of layers in ways that clearly demonstrate the depth and power of this important and versatile tool set in Photoshop.
Even though The Adobe Photoshop Layers Book mainly confirms much of what I already know and use in my daily professional work with Photoshop, I still found some useful new nuggets of information in chapter 7 - Advance Blending with Blend If, which focuses on the use of the advanced capabilities provided in the Layer Styles dialog.
As a long time user of Photoshop I found myself often smiling at several of the example projects in The Adobe Photoshop Layers Book because they echoed things I have encountered on past projects. I was however left feeling that the examples used in the book needed a little fleshing out. I would like to have seen an example matrix-type approach with several different types of images featured to show a range of results, especially in the Exploring Layer Modes chapter.
Cons: Too general in some sections for experienced users. Although most parts of the layers coverage is comprehensive, deeper examples could improve an already fine book.
Pros: Excellent hints and tips. Comprehensive coverage of Photoshop layers for beginner and intermediate users. Lynch seems to do a good job of avoiding computer platform bias, so Windows and Mac OS X users alike will derive equal value from the book. Relevant for most recent versions of Photoshop including Photoshop CS, Photoshop CS2, Photoshop CS3, Photoshop Elements 5 and Photoshop Elements 6. This excellent, focused book and its companion CD will no doubt open the eyes of many beginners and intermediate users about the functional and creative capabilities of layers in Photoshop. Highly recommended.