Learn how to merge adjustment or fill layers in Photoshop and understand how merging affects your edits and file structure.
Adjustment and fill layers can be merged in different ways. You can merge them with the layer directly below, with all layers inside a group, with selected layers, or with all visible layers. However, an adjustment or fill layer cannot serve as the target layer for a merge.
When you merge an adjustment or fill layer with the layer beneath it, the adjustments are rasterized and permanently applied to that layer. Similarly, a fill layer can be rasterized without merging, giving you more control over when edits become permanent.
It's worth noting that adjustment and fill layers whose masks contain only white values don't significantly increase file size. Merging them purely to save space is unnecessary.
