Rasterize and Flatten Layer Effects in Photoshop

Applying Filters to Layers That Have Effects

Merge Down
Merge Down to Flatten Effects in Photoshop | View Larger. © S. Chastain

Adobe Photoshop includes layer effects such as bevels, strokes, shadows and glows to change the appearance of layer contents. The effects are nondestructive, and they are linked to the layer contents. They can be modified to change the effect on the layer contents at any time.

What Does Rasterize Mean?

Type and shapes in Photoshop are created in vector layers. No matter how much you enlarge the layer, the edges remain sharp and clear.

Rasterizing a layer converts it to pixels. When you zoom in, you can see the edges are made up of tiny squares.

When you rasterize a layer, it loses its vector features. You can no longer edit the text or scale text and shapes without losing quality. Before you rasterize a layer, duplicate it by choosing Layer > Duplicate. Then, after you rasterize the duplicate layer, you have the original saved if you ever need to go back and make any changes.

Rasterizing Before Applying Filters

Some Photoshop tools—filters, brushes, eraser and paint bucket fill—work only on rasterized layers, and you'll receive a message to warn you when you try to use a tool that requires it. When you apply layer style effects to text or shapes and then rasterize the layer—which is necessary with filters—only the text or shape content is rasterized. The layer effects stay separate and editable. Usually, this is a good thing, but if you then apply filters, they apply to the text or shape and not the effects.

To rasterize and flatten the entire layer contents, create a new, empty layer in the Layer palette below the layer with the effects, select both laters and merge them (Ctrl+E on Windows/Command+E on MacOS) to a single layer. Now everything is affected by the filter, but the layer effects can no longer be modified.

Smart Objects Alternative

Smart objects are layers that preserve the image pixel and vector data with all its original characteristics. They are a powerful tool you can use to speed up the workflow while maintaining the image quality. When you are warned that a layer must be rasterized before a specific filter can be applied, you are often given the option to convert to a Smart Object instead, which allows you to perform nondestructive editing. Smart objects keep the original data intact while you rotate, apply filters and transform an object. You can use Smart Objects to:

  • Scale, rotate, skew, warp and transform perspective
  • Work with vector data from other applications that would be rasterized in Photoshop
  • Do nondestructive filtering. You can edit filters applied to Smart Objects
  • Update all Smart Objects that share the same source file by altering only one file
  • Reduce the size of files.
  • Work with low-resolution images as placeholders; then replace them with high-resolution versions

You cannot use Smart Objects to do anything that alters pixel data, such as painting, dodging, cloning and burning.