How to Merge Layers in Photoshop CS6

By Barbara Obermeier

While layers are great, they can make your image file go from slim and trim to bulky and bloated. Photoshop CS6 allows a solution with merging layers. With multiple layers, you not only get a larger file size that slows your computer system performance, but you’re also limited to the file formats that allow you to save layers. To curb large file sizes, you have a couple options:

  • Merging layers: Combines visible, linked, or adjacent layers into a single layer. The intersection of all transparent areas is retained. You can merge layers or layer groups. You can also merge adjustment or fill layers, but they can’t act as the target layer for the merge. Merging layers can help decrease your file size and make your document more manageable. You’re still restricted to the layer-friendly file formats, however.

  • Flattening an image: Combines all visible layers into a background. Photoshop deletes hidden layers and fills any transparent areas with white. Flattening is usually reserved for when you’re completely finished editing your image.

When you convert an image from one color mode to another, that conversion may cause the file to flatten. Look out for the warning dialog box that prompts you of this result, and go back and save a copy of your file as a native Photoshop file, thereby preserving your layers.

You can merge your layers several ways. To use the first option, follow these steps:

  1. Ensure that all the layers (and layer sets) that you want to merge are visible.

    [Credit: ©iStockphoto.com/imv Image #2053920]
    Credit: ©iStockphoto.com/imv Image #2053920
  2. Choose Merge Visible from the Layers panel menu or the Layer menu.

    All visible layers are smushed into a single layer.

Hold down Alt (Option on the Mac) when choosing Layer→Merge Visible. Photoshop merges those layers onto a new layer while leaving your original layers intact.

You can also merge layers by following these steps:

  1. Position the layer or layer groups that you want to merge adjacent to each other in the Layers panel.

  2. Select the top layer of those you want merged.

  3. Choose Merge Down from the Layers panel menu or the Layer menu.

    If the top layer is a layer group, the command is called Merge Group.

    Merge Down merges your selected layer with the layer directly below it.