PSD
A layered working format that preserves layers, masks, adjustments, text and smart objects for continued editing.
Measured in
MB
In depth
PSD is a working file, not a delivery one: it keeps the entire editing structure so a composite can be revised, at the cost of very large sizes and limited compatibility outside its own ecosystem. Files above two gigabytes require the extended PSB variant, which heavy retouching and large panoramas reach easily.
Examples in practice
A beauty retouch with forty layers is kept as a PSD master and exported to TIFF and JPEG for delivery.