There are times when you may want to merge layers together so you can apply effects to all of the image data contained in the merged layers at once. Also, individual layers and their related information can create large file sizes. Merging layers can reduce the size of the file by condensing multiple layers into one.

 

With Photoshop CS, you can merge linked layers, you can merge down, and you can merge visible layers. One thing to keep in mind when merging layers is that once they are merged, you cannot select and work with them separately as before.

 

To merge linked layers, first use the process described previously to link together any layers of your choice. Once the layers are linked, click the small arrow in the upper right of the layers palette and choose Merge Linked from the menu of options.

 

 

In this example, the title layer and sunflower 1 layer have been linked.

 

 

When the linked layers are merged, there will be one less layer in the list

 

 

Here, the linked layers have been merged into one layer called title (notice that the sunflower 1 layer is missing). The image data from the sunflower 1 layer has been merged with the data from the title layer.

 

You can also use the Ctrl + E keyboard shortcut to merge the linked layers if you prefer.

 

The second merging option available to you is referred to as merging down. To merge down, you must choose two layers that are adjacent in the list. Select the top layer from the two, and then click the small arrow in the upper right of the layers palette to display the layer menu options. From the list of menu items, click on Merge Down to merge the selected layer with the one immediately beneath it.

 

 

In this example, the sunflower 2 layer has been selected. Clicking the Merge Down option from the layer menu will merge the sunflower 2 layer with the sunflower 1 layer.

 

Still another way to merge layers is use the Merge Visible option. To merge layers in this way, first make all of the layers you do not want to merge invisible. You can do this by clicking on the eye icons at the left of the Layers palette.

 

When the layers that you want to merge are the only ones that are visible, select one of the visible layers, and then choose Merge Visible from the layer menu. Alternatively, you can use the Shift + Ctrl + E keyboard shortcut to merge the visible layers.

 

With any of these merging techniques, you can always choose Edit ->Undo Merge Linked, or Edit ->Undo->Merge down, or Edit->Undo->Merge Visible as the case may be, to undo the merge. This will work as long as you undo the merge immediately after it is performed.