TIFF, PSD, JPEG, PNG, PSB–Oh my! What are all these formats? Which one is for what purpose? Is there a rhyme or reason to using them? I’m glad you asked.
Photoshop has lots of file formats
Prove it by choosing File > Save As… That dialog box has lots of choices! The big five formats for photographers are marked with a red star.
Photoshop format .psd
The extension .psd stands for Photoshop document. It’s the original format for files with layers. It and it’s big brother .psb, are the only formats that support all of Photoshop’s features. I use .psd files to save my master working files using pixel based layers, adjustment layers and the rest unflattened in the ProPhoto colorspace. These layers hold all of my retouching, compositing and Photoshop magic. These never leave the studio. .Psd files saves 8-bits and 16-bits per channel and HDR (High Dynamic Range) 32-bits per channel. These files are limited to 2 gigabytes.
Large Document Format .psb
I call this one Photoshop BIG! This one supports all Photoshop features up to 300,000 pixels in any dimension. It works with 8, 16 & 32-bits per channel. It saves files larger than 2 gigabytes. I use this format when working with Smart Objects. They can add a lot of size to a master file in a big hurry. Their flexibility is completely worth it! The added benefit is that I can tell at a glance when a file is pixels only (.psd) or has Smart Objects (.psb.) Read about duplicating Smart Objects.
Compatibility for PSD & PSB
All versions of Photoshop and Lightroom can’t open the most current versions of .psd and .psb files because not every version of Photoshop supports layers (PS 1.0. 2.0 & 2.5 come to mind) nor does Lightroom. To be able to open them a flattened layer has to be created and stored in a hidden place in the document. It’s called maximizing compatibility. To use it go the the Photoshop menu (Mac) > Preferences (Edit > Preferences in Windows) > File Handling. Choose Always.
If you have seen a pesky window asking if you want to “maximize compatibility” for the file it’s set on Ask. Never saves only the layers. .Psd and .psb files with Never set will show an icon in Lightroom instead of a thumbnail or enlarged view.
JPEG Format .jpg
JPEG stands for Joint Photographers Expert Group. This format is really a compression routine. The JPEG specification retains all color information in an RGB file. It compresses the file size by selectively discarding information. It decompresses when it’s opened. More compression can drastically reduce the image quality. Save JPEGs at the Maximum quality setting, usually 10 or 12. This strategy will most often result in a file indistinguishable from the original’s quality. JPEGs are used on the web, in email and for making prints at labs as well as on the printing press. The format supports RGB, CMYK & Grayscale color modes. It does not support transparency.
Portable Network Graphics .png
The use of .png files are an alternative to the GIF (Graphics Interchange Format.) .png files handle RGB, Indexed Color, Grayscale & Bitmap mode photographs without alpha channels. They do support transparency in both RGB and Grayscale. These 24-bit photos produce background transparency without the “jaggies.” These files tend to be larger than JPEG, but are popular in many multimedia and online uses.
Tagged-Image File Format .tif (a.k.a. TIFF)
The TIFF file is the most universally accepted format. It is honored by almost all paint, image editing and page layout applications. Most desktop scanners produce TIFF images. TIFF supports RGB, CMYK, LAB, Indexed Color and Grayscale modes with alpha channels and the Bitmap mode without alpha channels. The maximum files size is 4 gigabytes. While Photoshop can save TIFF’s with layers, many applications will only display a flattened version. Photoshop TIFF files can be 8-bits, 16-bits or 32-bits per channel. 32-bit HDR files can be saved as a TIFF file as well.
The options for TIFF files include several compression options. Personally I am not a fan of compression. TIFF offers Lossless which makes the file smaller without taking away detail or color information. Lossy schemes remove image quality.
None – No compression. This is the best choice for saving a TIFF file. Period. Storage space is super cheap and the Internet is reasonably fast. There is no reason to compromise on quality.
LZW (Lemple-Zif-Welch) – Lossless compression that works best with large areas of a single color.
ZIP – Similar to LZW, ZIP works best with images of large areas of a single color. This takes longer to save as it has to analyze and compress the file.
JPEG – Same as for the JPEG format
RLE – Run Length Encoding is a lossless compression routine supported by some common Windows formats. Leave it checked.
ZIP – See above
Discard Layers and Save a Copy – Best practice says to save layered files as .psd or .psb. Flatten a copy to save as a TIFF.
How I use the Big Five
The dot three letter extension on a file I produce in Photoshop tells me instantly whether it’s a master file for studio use only, for the web or for high quality print. Here’s the breakdown.
Master files are my work product. These are never meant for client delivery. They contain my style of working in Photoshop. We all have our own, unique ways of working in Photoshop. Master files are where we do that work. I never flatten any layers in a master file. My master files are identified with the extensions .psd and .psb.
I use the .psd format to save layered master files containing only pixels. I save layered files with Smart Objects in the .psb format because using Smart Objects can greatly increase the file size.
Files I deliver to my clients are saved from duplicates of my master files. They are flattened, converted to 8-bits per channel and have the appropriate colorspace applied.
JPEG & PNG
I use JPEG’s for client uses on websites and social media. I also deliver JPEG’s for layout programs when the client specifies them. I provide .png files when transparency is required.
The TIFF format is for the highest quality deliverables. A client who is creating a printed billboard, a trade show display, an exhibition print or printing a brochure or a poster receives a flattened TIFF file, uncompressed, in 8-bits per channel and in the appropriate color space.