PNG(Portable Network Graphics):
PNG (Portable Network Graphics) was originally meant to replace the GIF format (PNG also stands for "PNG not GIF"). That never happened and GIF files are still in wide use today, yet the PNG format improves upon the GIF format in nearly every way. It even improves on the JPEG format. While JPEG files support 24-bit color (16.7 million colors), PNG files support up to 48-bit color, giving us more than 1 billion possible colors! That may sound impressive, but even JPEG files support more colors than the human eye can see, so any real world differences between 24 and 48-bit color are minimal at best.
You can even re-save the same PNG file multiple times without degrading its quality, whereas JPEG files look worse each time you re-save them. With over a billion possible colors and lossless compression, PNG is a great choice for saving digital photos as high quality originals. The downside, though, is that PNG is not as widely supported as the JPEG format, and PNG does not support CMYK color, which means commercial printers can't use them. For everyday viewing and sharing of your digital photos, the JPEG format is still more useful and convenient, even if the image quality isn't as good.
PNG's main advantage over GIF files, besides far exceeding GIF's 256 color limit, is that it can reproduce a full 256 levels of transparency compared with GIF's single level, giving us smooth transitions around edges without having to worry about matching the edges with the background color. PNG files are also usually smaller than GIF files, so they'll load even faster in a web browser. Unfortunately, older web browsers may not support the PNG format, which means GIF is still the safest choice when browser compatibility is your main concern. Also, while GIF supports animations, PNG does not. PNG files are most often used in multimedia programs like Flash as well as Keynote and PowerPoint presentations.
Even though TIFF files are capable of storing all of the layers, adjustment layers and other elements you've added in Photoshop, it's generally recommended that you save all those elements in your master PSD file, then use the TIFF format to save a flattened version of the image for print. This makes it easy to tell just from looking at the file extension which version of your image is the master working file (.psd) and which is the flattened, print-ready version (.tif). Also, many commercial printers will ask for a flattened version of your TIFF file.
With InDesign now being able to import and work directly with layered Photoshop PSD files, and both the PSD and PDF formats gaining popularity in the print community, TIFF isn't quite as important as it once was, but it remains the print industry standard and enjoys widespread support.
The most important thing to remember is to save your working Photoshop file as an unflattened PSD file to use as your master copy, which will preserve all of your layers, channels and so on in Photoshop's native file format, allowing you to return to your work at any time. From there, you can save a copy of your image in one of the other six formats depending on where the image is headed (print, the web, or a multimedia program) or which format your printer has requested.
PNG (Portable Network Graphics) was originally meant to replace the GIF format (PNG also stands for "PNG not GIF"). That never happened and GIF files are still in wide use today, yet the PNG format improves upon the GIF format in nearly every way. It even improves on the JPEG format. While JPEG files support 24-bit color (16.7 million colors), PNG files support up to 48-bit color, giving us more than 1 billion possible colors! That may sound impressive, but even JPEG files support more colors than the human eye can see, so any real world differences between 24 and 48-bit color are minimal at best.
You can even re-save the same PNG file multiple times without degrading its quality, whereas JPEG files look worse each time you re-save them. With over a billion possible colors and lossless compression, PNG is a great choice for saving digital photos as high quality originals. The downside, though, is that PNG is not as widely supported as the JPEG format, and PNG does not support CMYK color, which means commercial printers can't use them. For everyday viewing and sharing of your digital photos, the JPEG format is still more useful and convenient, even if the image quality isn't as good.
PNG's main advantage over GIF files, besides far exceeding GIF's 256 color limit, is that it can reproduce a full 256 levels of transparency compared with GIF's single level, giving us smooth transitions around edges without having to worry about matching the edges with the background color. PNG files are also usually smaller than GIF files, so they'll load even faster in a web browser. Unfortunately, older web browsers may not support the PNG format, which means GIF is still the safest choice when browser compatibility is your main concern. Also, while GIF supports animations, PNG does not. PNG files are most often used in multimedia programs like Flash as well as Keynote and PowerPoint presentations.
TIFF(Tagged Image File Format):
Like PSD files, TIFF (Tagged Image File Format) is one of the few file types that support all of Photoshop's features and is another great choice for archiving your images, with lossless compression that allows you to save photos with the highest possible image quality. The quality comes at a price though, as TIFF files can be very large, especially when compared with JPEG files. TIFF is the universally accepted standard for images destined for commercial printing and is compatible with virtually all page layout programs like QuarkXPress and InDesign.Even though TIFF files are capable of storing all of the layers, adjustment layers and other elements you've added in Photoshop, it's generally recommended that you save all those elements in your master PSD file, then use the TIFF format to save a flattened version of the image for print. This makes it easy to tell just from looking at the file extension which version of your image is the master working file (.psd) and which is the flattened, print-ready version (.tif). Also, many commercial printers will ask for a flattened version of your TIFF file.
With InDesign now being able to import and work directly with layered Photoshop PSD files, and both the PSD and PDF formats gaining popularity in the print community, TIFF isn't quite as important as it once was, but it remains the print industry standard and enjoys widespread support.
EPS(Encapsulated PostScript):
EPS (Encapsulated PostScript) is another print industry standard format that's been around for quite a while, but its use has been in decline over the years. EPS files are not really image files in the traditional sense. Instead, they contain a series of instructions for how a printer should reproduce the image. They can be imported into most page layout programs, but the "encapsulated" part means the files are essentially locked and can no longer be modified unless they're re-opened in Photoshop. A preview image must be embedded in the EPS file when you save it in Photoshop if you want it to be viewable onscreen when working in your page layout program, otherwise you won't be able to see it until the layout is printed. While EPS remains an industry standard format, you probably won't use it very often unless it's the format specifically requested by your commercial printer.PDF(Portable Document Format):
Finally, while most people are familiar with PDF files for viewing, sharing and printing electronic documents (hence the name Portable Document Format), PDF is also gaining in popularity as a great choice for saving images destined for print. Like the PSD and TIFF formats, PDF supports and preserves all of Photoshop's features, including the ability to use spot colors, something the EPS format does not support. PDF gives you the choice of either JPEG compression, complete with a Quality setting to balance image quality with file size, or lossless ZIP compression. And the PDF format benefits from the fact that anyone with the free Adobe Reader installed on their computer can view the image.The most important thing to remember is to save your working Photoshop file as an unflattened PSD file to use as your master copy, which will preserve all of your layers, channels and so on in Photoshop's native file format, allowing you to return to your work at any time. From there, you can save a copy of your image in one of the other six formats depending on where the image is headed (print, the web, or a multimedia program) or which format your printer has requested.
