iStock - Stock Illustration Training Manual
4.2 - File Extensions and Naming
All of the files that you submit must end in the proper extensions. For example, your AI10 EPS will end with “.eps”, and your JPEG will end in “.jpg” or “.jpeg”. Any file submissions without proper file extensions will be declined.
When naming your files, it is important to name them appropriately. For example, if you have drawn a woman shopping, your EPS file might be named “Woman_Shopping.eps” or “WomanShopping.eps”. Try to avoid naming your file using numbers or other personal naming systems.
If you're including a separate ZIP folder (optional) containing additional file formats (such as AI, FH, Corel or PDF files), please ensure all files end with the proper extensions and are named clearly. This is especially important if you're including multiple color versions of the same illustration, as it can be confusing trying to find the right image.
DO
Add the appropriate file extension to any files you upload
Name your files based on the subject matter of your illustration
DO NOT
Submit images without file extensions
Submit files named with a personal naming system (example: icon_043845.eps)
Correct and incorrect file naming and extension examples: