Think of layers in Photoshop like adding another page. The difference is that the layers are placed over the same position or section, kind of like a stacked pile of papers. But, in using layers, you can change transparency, effects, add text and do numerous other things. The greatest advantage is that you can move the layers anywhere you want on your canvas. In essence, you are creating a canvas with stacked images that can be situated anywhere using various features to achieve the look you want.
Adding a Layer in a Photoshop is actually quite simple. Notice your 'Layers' menu to the right. To add a layer, click on the 'Create a New Layer' button:
You can add as many layers as you want by clicking this button over and over again. Photoshop will give it the default name such as 'Layer 1'. To rename the layer, double-click over the name in the layers menu and retitle it. Multiple layers can be used by having several images, with each image on one layer.
Tip: When using layers, it is important to keep them unlocked. In other words, if you want to move your layer around, it cannot have the lock image next to it as seen here in 'Background'. The 'Background' layer is always the original file that serves as the background. To unlock this layer, simply double-click over the name area of 'Background'. In case you do not want a layer to move, you will want to purposely lock a layer. To do this, select a layer and click on the lock icon next to the 'Fill' option in the layers menu.
If you use multiple layers and want them grouped into categories, you can do this in Photoshop by grouping layers.
To group layers, add a Group folder by clicking on the 'Create a new group' button in the Layers menu:
Once you click this button, a new Group folder will appear in your Layers menu:
To rename the group, simply double-click over the name and type a new name. To group layers, simply select a layer, hold down your mouse and drag the layer into the group folder.
Layer masks allow you to edit a layer without effecting the original image. For example, you want to create a gradient on a layer, but you do not want to effect the layer. You can do this with layer masks.
To add a layer mask, click on the 'Add Layer Mask' button in the Layers menu:
To select the layer mask, click on the layer mask thumbnail as shown here:
Tip: To make sure you are editing the layer mask without effecting the original layer, make sure the link button right next to the layer mask is selected as seen here. If it is not linked, the link button will not be visible.
If you ever want to delete a layer mask, simply have the layer mask selected, right-click and click on 'Delete Layer Mask'.
Merging layers can be used if you want to merge more than one layer so that you can work on it as one layer. This is a tool you should be careful with because once you merge layers and close your file, this cannot be undone. Merge layers when you are certain you want to do this. This can also be a tool to use if you want to merge layers to make blending easier.
To merge layers, select at least two layers in the Layers menu. Then click on the drop-down menu to the right and select 'Merge Layers':
Once the layers are merged, it will be converted into one layer:
Transparency is the most used tool when using multiple layers. This allows multiple layers to be visible on one canvas.
To change transparency, select a layer and click on or enter a number in the percentage bar of the 'Opacity' option:
Tip: Want to change how it blends with other layers? Select the layer, click on the 'Blending Mode' menu and change from Normal to Multiple, Lighten, Screen, etc. by clicking on any of the options listed.
Using gradients gives you blending options that you can use with multiple layers. This is good for blending edges of images on layers so that they look like they are blending in with one another.
To add a gradient, you will need to first add a layer mask. To add a layer mask, click on the layer and click on the 'Add Layer Mask' button:
Select the layer mask and make sure the link button is present (link image in between the layer mask and layer). From there, select your gradient tool:
Select your options from the gradient menu at the top of your screen. You can select the gradient style, gradient type, blending mode, opacity and many other options:
Once you have your settings selected, hold down your mouse over an area of the layer mask in your file and drag to the right, left, top or bottom. The best way to use gradients is to become familiar with your gradient settings and play with the many different options. Over time, you will learn your preferences.