If you aren't sure which image format is right for you, ask yourself the following questions:

• In what application do I intend to use the image (Microsoft Word, QuarkXpress, Adobe Illustrator, Adobe Photoshop, CorelDRAW, etc.)?
• What file formats can that application accept?

If you don't know which formats are compatible with your product, check its help documentation.

If your application doesn't accept raster images, you cannot use JPEG or GIF. If it doesn't accept vector images, you cannot use EPS or WMF.
If you need the subject isolated from the background choose PSD, the native Adobe Photoshop file format. PSD files come in layers on transparent backgrounds and blend seamlessly with the background of your choice.

Which format should you pick once you've narrowed the options down? Below are some very general rules of thumb. While there are numerous exceptions to these rules, and the information presented here should in no way be considered complete, this should help you get started.

Use JPEG for:

• images with many colors
• rendered 3D graphics
• photos
• paint programs (like Photoshop or Paint Shop)

• In general about JPEG (or jpg): The JPEG format is a lossy, compressed file format. The original file size of the image you purchase may be 10, 20 or more MB but the JPG that you download will be only approximately 10% of that size. After you save the file in an uncompressed format, e.g. TIFF, EPS or BMP, it will expand to its original size. When using JPEG images no image degradation is noticeable after a single compression/decompression cycle. However, further compression(s) to and from the JPEG format will degrade the image quality to an extent that eventually it will become visible. To retain maximum quality in these images simply avoid re-saving the image in JPEG format and use uncompressed formats such as TIFF, EPS or BMP or a loss-less compression format such as TIFF with LZW compression.

Use PSD for:

• certain Adobe products (Photoshop, ImageReady, Illustrator, etc.)
• images you'd like to edit, using layers (a layer is an image-editing feature that allows different parts of an image file to be created and modified independently)

Use GIF for:

• black and white images
• images with large areas of solid color (cartoons, line art)
• images you intend to make transparent
• paint programs (like Photoshop or Paint Shop)

Use EPS for:

• Macintosh systems
• PostScript-compatible printer (may be required)
• images you intend to scale
• programs that accept vector images but don't take WMF
• draw programs (like Illustrator or CorelDRAW)

Use WMF for:

• Windows systems
• Microsoft applications
• images you intend to scale
• programs that accept vector images but don't take EPS
• draw programs (like Illustrator or CorelDRAW)