Should I upload Tiff or JPEG files, and what about image quality

The system does accept Tiff file; however we’ve found that most web browsers won’t allow TIFF uploads, the exception being Apple’s Safari browser.  We recommend saving your files in a JPEG format after editing them to reduce their total size and enable online upload.  This won’t compromise the file quality when printing.  It is most important to preserve the range of colors while making editing changes.  Once you’ve completed those changes, convert the color space to sRGB and save the file in JPEG format (with the color space embedded) for the best results.