File Formats for Images in Your E-Mail Marketing Messages - dummies

File Formats for Images in Your E-Mail Marketing Messages

By John Arnold

Using images — any type of graphic file — in your e-mail marketing communications gives your messages it pizzazz but also requires careful planning. Whether you obtain your images with a digital camera or buy them online from a provider of royalty-free stock photography, make sure that your images are formatted for use in e-mail:

  • Use a file format that e-mail browsers can read. An image file format is the type of compression used on an image to limit the amount of data required to store the image on a computer. Compression changes the amount of space the image takes up when stored on a computer, and image compression causes the graphics to display differently (especially when you reduce or enlarge the dimensions of the image). The three best file formats to use in e-mail browsers are

    • JPG or JPEG (Joint Photographic Experts Group): This format is a standard for Internet and e-mail images, and it works well for most images.

    • GIF (Graphics Interchange Format): This format is best for images with only a few colors.

    • PNG (Portable Network Graphics): This format is similar to GIF compression but has the ability to display colors more effectively.

    If your image isn’t already in one of these three formats, use a graphic design application or an image editor to save the image as a JPG file.

  • Check your file size. The file size of your image refers to the amount of data your image contains measured in kilobytes (K). Images should be less than 50K to download quickly enough for most e-mail users. If an image you want to use in your e-mail is more than 50K, you can change the file size in a graphic design or an image-editing application.

    • Reduce the dimensions of the image. Smaller images contain less data.

    • Reduce the image resolution to 72 dpi or less. Image resolution, also known as dots per inch (dpi) or pixels per inch (ppi), refers to how many dots (or pixels) are in each inch of your image. The more dots per inch, the more detail your image is capable of displaying. More dots require more data, however, so images with higher resolutions download and display more slowly than images with lower resolutions.

    Using 72 dpi provides enough resolution to appear properly on a computer screen, but images printed at 72 dpi are likely to appear fuzzy. If your audience is likely to print your e-mail and it’s important that your images are printed with more definition, link your audience to a PDF version of your e-mail containing print-quality images 300 dpi or higher.