3 Masking Concepts
In my years of teaching Photoshop I have always said to students that if they think of Ps in black & white it will really help them to simplify this complex application. This statement originates from a time when I started working in Ps with version 2.0 which predated Layers that were introduced years later in v3. Back in those days you had to copy and paste from one image into another and precisely place the image where you needed it to be; and if you needed to layer effects like adding a drop shadow, that would need to be added before the second image were pasted in place. Did I mention that there was also only one Undo?! The History panel was not added until version 4. In addition to this calculated way of working I had relied heavily on Channels for various operations such as making selections, masking and color correcting, as Color management was not introduced into Ps until v5.
That was a brief history of Photoshop but how does it relate to thinking of Ps in b&w to master it? The answer is Channels. Photoshop’s individual [RGB] color Channels, are shown by default in black & white although you could change them to display in their respective RGB or CMYK color through Preferences, but an understanding of how they work may have an impact on mastering masking.
You have probably learned how to use Layer Masks to make local edits with Adjustment Layers, masks with Pixel Layers to create composites, and were probably taught the associated phrase of White Reveals, Black Conceals. This phrase translates directly to Channels and this section will dive deeper into these concepts to help you better understand masking and fine tuning selections.
Layer Masks
I will begin this section with a brief review of Layer Masks, as there are various ways to create and use layer masks in Photoshop from making local adjustments, or compositing layers, and this section will be a refresher on some of the techniques that you may have previously learned.
Layer Masks with Adjustment Layers
Adjustment Layers can be added via the Layer menu or from the shortcut located at the bottom of the Layers panel as shown in Figure 3.2. The shortcut on the Layers panel includes both the New Fill Layer, as well as the New Adjustment Layer options which are a separate line items in the Layer menu.
When you add a new fill or adjustment layer to an image a Layer Mask will automatically be created to allow you to make local adjustments to a photo as seen Figure 3.3. The mask is a solid white color by default [White Reveals], which shows the areas that are affected by the adjustment, or the areas where the adjustment is revealed. You can use any painting, or selection tool with a fill that allows you to add black to the mask [Black Conceals], which will hide, or erase the adjustment. The benefit of the layer mask is that you are not making a permanent adjustment, so you can use any of the tools that allow you to add colors to paint or fill a white area with black, or a