In Adobe Photoshop, blend modes, in their simplest form, are devices that control how pixels in two separate layers interact with and affect each other. The base is the bottom layer and the blend is the upper layer with the result coming from the blending of the two. For many, blend modes are a mystery to how they work, but yet can provide essential tools to photographers and digital artists for what they can be used for and how they can improve your work.
In his book The Hidden Power of Blend Modes in Adobe Photoshop, author Scott Valentine takes the mystery out of working with blend modes and provides concrete examples of how they work and what they can be used for. The Hidden Power of Blend Modes in Adobe Photoshop is 224 pages in length and is contained in seven chapters.
Chapter One, "Introduction," begins by delving into some general concepts that you need to understand if you want to work with blend modes. After a brief introduction, the author gets right down to work, explaining just how blend modes work with illustrations to explain some basic concepts. He then finishes with exactly what you need to know about in Photoshop to get the most benefit out of blend modes as well as why you should also use a digital tablet when working in Photoshop.
Chapter Two, "General Techniques," describes the basic building blocks of working with blend modes. These are the fundamental methods that you need in your toolbox. These include basic, inverted, and filtered self blend, fill blend, selection blend, painting blend, and adjustment blend. Here you learn what each of these is and how to combine them, work with them, and how they interact. You will also learn about the use of blending layers, layer styles, smart objects, building reference images, and other techniques to have at the ready.