Layers are one of the most basic aspects of image editing software. Understanding and learning how layers work is essential for anybody who wants to use post-processing to improve their images. Layers are such a rudimentary part of an editing workflow that once you start editing your images on a regular basis it will feel as a second nature to you. But it is important to get into a habit of using them correctly and structure them orderly to avoid mistakes and confusion later. Today I would like to introduce layers in Adobe Photoshop, describe their basic functions and structure. This tutorial is for people who are new to image editing software and are looking to learn how layers work.
Note: I am using Adobe Photoshop CS6 as an example, but many other programs also employ layers and use similar concept for editing. However, Layer functionality has been extensively revised in Photoshop CS6 so some of the techniques described below may work differently with older versions of Photoshop. For Mac users, wherever [Ctrl] key is mentioned, substitute it with [CMD] key.
You can think of layers as transparent pages which you can add on top of your original image to make changes and additions. When a new layer is created it can be moved and edited independently form others. You can duplicate your image and then apply effects without destroying the original. Having layers gives you much more control. You can apply effects, change only parts of your photo or change the opacity of a top layer, so that a layer below it is partially visible. Additionally you can use masks and blending options to create interesting effect.
By default a layer tab is located in the bottom right corner of Adobe Photoshop workspace, if it’s not there, then you can activate it by going to Window>Layers on the top Navigation Bar or hitting [F7].
When you open a file or create a new one, an initial layer called ‘Background’ is automatically created. It is locked by default, which is indicated by a lock icon. When opening a photo for editing, I suggest always keeping this background layer untouched, to have an original image for reference.
Creating new layer
To create a new layer click on a ‘New Layer’ icon in the bottom right corner or go to Layer>New>Layer. Additionally, you can also hit [Shift]+[Ctrl]+[N] keys. Once you create a new layer, it is usually a good idea to give it a name specific to its effect or its change relative to the rest of the file. This is a useful habit to acquire because as your skill develops and you start applying numerous different changes and effects to your photos, and grow a large list of layers. Once you have identifiable names, you will easily be able to navigate through them simply by looking at their titles. You can specify a layer name during its creation or you can change it later by double clicking on its title.
Moreover, you can also toggle an eye icon on/off next to a layer to make it disappear or become visible on the actual file. You can also change the color of a layer if you want to have a specific designation. This can either be done during creation or by double clicking on a layer. Additionally, you can change layer’s position by simply dragging it up or down. Remember that the top level always has a priority over the bottom one and will always cover it. You can also customize the size of a layer’s thumbnail by double clicking on it and selecting a preferred size.
There will always be instances where you would need to duplicate a layer. To do this, you can drag a layer you want to copy to a ‘New Layer’ icon and then let go, this will make a duplicate copy. You can also press [Ctrl]+J keys or got to Layer>Duplicate Layer on the top Navigation Panel.
Moreover, you can combine two or more layers. To do this hold [Ctrl] and click on every layer you would like to merge, then continue holding [Ctrl] and hit [E]. You can also go to Layer>Merge Layers on the top Navigation Panel. Additionally, you can merge all layers that are toggled as visible by hitting [Shift]+[Ctrl]+[E] or going to Layer>Merge Visible. Or you can just right click on selected layers and choose these options. Remember that image formats such as JPEG do not support layer so if you save your photo in this format, all your layers will flattened into one.
Mask is a special type of layer. It is actually linked to a layer you are applying it to and the mask is actually positioned within that layer. It will appear as a white box next to that layer’s thumbnail with a link icon in between. White parts identify where the mask is present while black part shows where the layer can be seen through to the one below. Using an Erase tool will create black areas while using a Brush tool with any color will create white areas on a mask.
Just like Mask, Text Layers are a bit different from others and will be identified by ‘T’ on its thumbnail. The text of this layer can still be changed and effects can be applied to it. But if you want to use any tools such as Brush, or Erase on this layer it will not be possible. To use them you will need to rasterize the Text layer. Once you rasterize it, you will not be able to edit the text.
Applying changes to layers
There are numerous changes and effects that can be applied to layers. Blending modes are available in various configurations. They are often used by photographers to make interesting effects. When this mode is set to normal it means no blending effects are applied.
Below blending mode you will see various locking options to lock specific aspects of a layer.
Opacity is responsible for how transparent a layer is. At 100% the layer is completely visible and at 0% it is completely transparent, everything in between makes the layer more or less visible. Fill is similar to opacity but it will only affect the image and keep any layer effects at 100%.
You can also link one layer to another. This is usually done to be able to move them together. To do this just select layers and click on a link icon.
Adding blending options will apply them to a layer and create a list of used effects below that layer. These effects can be customized through blending options menu which can be accessed by double clicking on effect name or right clicking on the layer and selecting ‘Blending Options.’
Creating a new fill or adjustment layer will consequently create a transparent layer that can have numerous changes applied to it. You can change levels, saturation, curves and much more with this layer and it will affect all the layers below
To delete a layer you can select it and hit [Delete], or drag it to recycling bin icon, or just select the layer and hit that icon or right-click the layer and choose ‘Delete Layer.’
Once you start applying a lot of different changes and effect to your photo you will realize how important it is to name and carefully organize your layers. To help you organize, Layers tab offers folders to compartmentalize groups of layers into sections. To create a folder click on a little folder icon in the bottom right corner and drag all relevant layer inside of it. You can name and reposition folder but remember that top to bottom hierarchy still applies.
Quick tip: If you wish to see “Before and After” view of your current project, press and hold [Alt] key and click on Eye icon of the background layer (which is all the way on the bottom). This will hide all the other layers on top, showing you just the initial layer. If you haven’t made any changes to the background layer you should see original look of your project. Holding [Alt] key and clicking on Eye icon again will make all the other layers visible and show you the final version of your project.
Photoshop CS6 has a new feature which makes it easier to sort and filter layers by various parameters. When working on an elaborate project a file can quickly grow to very large proportions and it’s not uncommon to have over hundred layers in one file. Previously, it was just a matter of giving very specific layer names, color identification and folder grouping. But now there is layer filtering.
Layer filtering can be found on the very top of a layer window. By default, you can filter by layer kind. Which breaks down to pixel layers, adjustment layers, type layers, shape layers and smart objects. You can also do a search by name. Additionally, you can sort by Effect, Mode, Attribute and Color which is essentially all the changes you can apply to a layer. Therefore, this new filter option streamlines the search on files with many layer and effectively makes Photoshop work more efficient.