Properties file created by Adobe Photoshop and Adobe Illustrator; stores settings for the "Save for Web" tool; saves the image format (JPEG, PNG-8, PNG-24, GIF, or WBMP), quality, size, and other optimization options; used for producing Web page images that use the same image format and quality specifications. The Save for Web dialog can be opened in Photoshop CS5 by selecting File ? Save for Web & Devices.... NOTE: Save for Web settings files more often use the .IRS extension.