Photoshop format (PSD)

Photoshop format (PSD) is the default file format and the only format that supports most Photoshop features besides the Large Document Format (PSB). Due to the tight integration between Adobe products, other Adobe applications like Adobe Illustrator, Adobe InDesign, Adobe Premiere, Adobe After Effects, and Adobe GoLive can directly import PSD files and preserve many Photoshop features. For more information, see Help for the specific Adobe applications; also see Saving images for use in video and Saving images for use in motion graphics.

When saving a PSD file for use in a previous version of Photoshop or ImageReady, you can set a preference to maximize file compatibility.

To maximize compatibility with previous versions of Photoshop and with other applications (Photoshop):

1. Do one of the following:
• In Windows, choose Edit > Preferences > File Handling.
• In Mac OS, choose Photoshop > Preferences > File Handling.
2. Choose Always from the Maximize PSD File Compatibility menu. This saves a composite (flattened) image along with the layers of your document.

Note: If file size is an issue or if you're only opening your files in Photoshop, turning off Maximize PSD File Compatibility reduces the file sizes significantly. In the Maximize PSD File Compatibility menu, choose either Ask to prompt you on whether to maximize compatibility when saving or Never to save your document without maximizing compatibility.

If you edit or save an image using an earlier version of Photoshop, unsupported features are discarded. Keep in mind the following features when working with earlier versions of Photoshop:

• Photoshop CS introduces nested layers, Hard Mix blending mode, Photo Filter adjustment layers, 56 channel limit, text on a path, support for files greater than 2GB, support for files greater than 30,000 pixels in any dimension, non-square pixels support, 16-bit layers, 16-bit patterns, and 16-bit Brushes.
• Photoshop 7.0 introduced the Linear Burn, Linear Dodge, Vivid Light, Linear Light, and Pin Light blending modes and the Layer Mask Hides Effect and Vector Mask Hides Effect advanced blending options.
• Photoshop 6.0 introduced layer sets, layer color coding, layer clipping paths, fill layers, layer styles, editable type, and advanced type formatting. Photoshop 6.0 also added new layer effects.
• Photoshop 5.0 introduced layer effects; however, effects added in later versions of Photoshop are not supported. Photoshop 5.0 also introduced color samplers, spot channels, and embedded ICC profiles.
• Photoshop 4.0 introduced adjustment layers and guides.