Lesson 3 – Layers and masks
Let's learn more about layers. When we open the image first time, it will become the first layer, which will be locked from editing and have the name Background.
Next what we do, we create the duplicate of our first layer by right clicking and choosing Duplicate Layer.
You also need to know that Photoshop has multiple ways and shortcut to perform the same or similar function. For example to duplicate layer we can. Hold Option Key(Alt for Windows) and double click on Background layer which will unlock Background , then keep holding Option Key, drag and drop the layer.
Layers are are sitting on each other and top layer will block the visibility of the layer below, unless it is transparent or if it is Adjustment layer, than the black color will reveal the information below and white will block it.
Let see how it works on practice. Let's paint with black brush on our first layer. As you can see nothing is happening, because the second layer on top is blocking the the one below. But when we click the eye icon and make the second layer invisible, we can see the first layer with black painting.
Now let's dive in to the concept of masking. Let's make visible our second layer and apply mask on it. And to ad a mask to the layer we need to click on rectangular icon below the layer panel. It will create white mask as adjustment layer, and as we mentioned before white in adjustment layer doesn't hide any information, thus at this point there won't be any changes on our view. To make it more visually compelling let's also create another layer below and paint it with some color. Now we go back, select the mask and start paining on it with black brush. As you can see in the areas painted black it will reveal our colored layer from below. So one more time. On the mask as well as any adjustment layer, white blocks the layer below and black reveals it. And it is worth to mention that grey colour will hold the same concept and hide or reveal information partially.
What is also very important to know is that by using masks we keep our work non-destructive and re editable.