In this tutorial, we are going to talk about merging and flattening layers and some of the different options available. I will go through the options I use when working on portraits.
This is the simplest to understand! This command simply merges all your visible layers (where the eye icon is turned on) into one layer. Here is what our Layers palette looks like with all our layers:
Let’s say we are done working with those layers and we want to merge all the changes we made into one layer instead of having 4 layers. You can Merge Visible (since all these layers are visible, as indicated by the eyeball to the left of each) using one of the following ways:
Right click on one of the layers in the Layers palette and choose “Merge Visible”
In the ‘Layer’ menu at the top, there is a “Merge Visible” option
Use the shortcut Shift + Ctrl/Cmd + E
Merging takes the effects of all your layers and merges them into one new pixel layer:
If you use the Merge Visible command and you have layers that are hidden, Photoshop will leave those layers there since it is only “merging visible” – get it?!?!
So if you start with this…
… and do the Merge Visible command, you will end up with this…
The Flatten command is very similar to Merge Visible. It basically flattens your image, or merges all your layers into one. The only difference is that if you go to flatten your image and you have hidden layers, it will ask you if you want to “Discard hidden layers?”
If you say “OK,” it will get rid of your hidden layer(s) upon flattening and leave you with one layer. If you say “Cancel,” it will keep your hidden layer and merge the rest, exactly the same as the Merge Visible command did.
The Flatten Image command is available by doing one of the following:
Right click on a layer and choose Flatten Image
Go to the ‘Layer’ menu at the top and choose Flatten Image
The keyboard shortcut Alt + Shift + Ctrl/Cmd + F
The Merge Down command lets you merge a layer with the pixel layer directly beneath it. It is available by doing one of the following:
Right click on the layer you want to merge down and choose Merge Down
In the Layers palette, highlight the layer you want to merge down, go to the ‘Layer’ menu at the top and choose Merge Down
Highlight the layer you want to merge down and use the keyboard shortcut Ctrl/Cmd + E
Is there really another option?! Yes!! I don’t think I’ve ever used this option, but I might as well mention it since we are on the topic. Who knows, you may find it handy one day! You can highlight multiple layers by holding down your Ctrl/Cmd key and selecting the ones you want to merge (or you can hold your Shift key to select multiple layers). You can then use the Merge Layers command, which will merge just the layers you have selected.
The Merge Layers command is available by doing one of the following, after highlighting the layers you want merged:
Right click on one of the layers and select Merge Layers
Go to the ‘Layers’ menu and select Merge Layers
The keyboard shortcut Ctrl/Cmd + E (this is actually the same shortcut as Merge Down)
Merging/flattening cuts down on the total file size of the document, so unless I need the layers available to edit or tweak at a later time, I always make sure to flatten my files before saving them. Just one more way to save a little hard drive space!