The PSB file format was first introduced in Adobe Photoshop CS in October of 2003 as an extension to extend the limitations of the .psd file format that Photoshop uses by default. If you have ever worked with high mega-pixel layered files in Photoshop you will quickly find out about the PSD limitations when you go to save the image and an error pops up suggesting you save as a PSB as photoshop will not save a PSD file formated image that is over 30,000 pixels in either direction or over 4 gigabytes in file size.
When To Use the PSB File Format
Due to file size limitation I use the PSB file format for all of my layered files as they occasionally grow to be larger than the 4GB limit as work progresses on them. The format sometimes saves out to be a smaller file which is always awesome. Due to the smaller file size reason I recently started delivering files to clients as PSB as well. This stems from most every finished file is delivered via the internet now as opposed to a physical drive. Thus if a given set of final files is 10% smaller the client can download them faster and they take up less space on the client’s computer. Given the file format has been out for 12 years I wrongfully assumed it would be fully integrated with all Adobe products and since the majority of files are used within Adobe products it seemed like a natural move away from PSD. Well things are not always as they should be.
When Not To Use The PSB File Format
In simple when sending files to a client or end user. In all cases I know of the PSD file formated images work just fine being opened in applications. I found out recently after a client called saying that InDesign wouldn’t import any of the 96 high resolution files I had sent totalling over 22GB in PSB file format (as it turns out 24.2GB in PSD). I was baffled at this oversight by Adobe. Thus as QuarkXPress (it still exists!?!) was the reason we hung on to TIFF file format for so long, now it seems InDesign will be the reason to keep holding on to the PSD file format although I’m sure there is other applications that don’t work with PSB files as well … *cough cough* were looking at you QuarkXPress!
PSD and PSB File Format Limitations
PSD: 4 Gigabytes max file size and 30,000 maximum pixel dimension
PSB: 4 Exabytes max file size and 300,000 maximum pixel dimension