Shape, line, image and text layers can be rasterised to create pixel layers. This "flattening" operation can be performed manually or automatically (when applying filters or retouch brushes).
Rasterisation has various uses:
For when the appearance of complex vector gradients or effects needs to be honoured, particularly for print artwork.
To convert a placed image layer to a pixel layer (for pixel manipulation). By default, many brush tools rasterise image layers before painting.
Inpainting: after cropping, inpainting may be used to tidy up an image's corners, but the inpainting may be using information outside of the crop area. Rasterising will discard this information and force the inpainting to use only what is visible.
To rasterise a shape, line, image or text layer:
On the Layers panel, select a layer, then choose one of the following from the Merge and Rasterise pop-up menu:
Rasterise—Rasterises the selected layer.
Rasterise & Trim—Rasterises and trims off-canvas content from the selected layer. Previously recorded macros will trim.
Rasterise To Mask—Rasterises the selected layer as a mask layer.
To rasterise a shape, line, image or text layer: