COMMREX.com Help Center:

Step 9: Enter Image Name, Select File Type and Click "Options."

The "Save As" pop-up window appears. Using the specific COMMREX Photo Codes for naming conventions, enter a name for your image in the "File Name" text box. Next, choose "File Type" and select "JPG-JPEG-JFIF Compliant" for color images, or "GIF" for black-and-white images. CRITICAL: for JPG images, click the "Options" button at the lower-right-hand corner of the pop-up window, and proceed to the next step:

   

Step 10: Adjust Compression

After clicking "Options," a new pop-up window named "File Preferences" will appear on top of the previous one. This is where you set the specifications for your image size and quality. Set the DPI (dots-per-inch) to 72, and set the compression level to 60, Choose Standard (NEVER use Progressive JPG)(NOTE: PSP 4.0 will not have this option, but later versions will), then click the "OK" button. The "File Preferences" window will close, returning focus to the "Save As" window.