My proposal: A simple, straightforward step-by-step guide with pictures that users can follow in order to check if their signature violates the signature rules. It would be available to view on the signature rules thread.
Tools required: Image editing software that can work across various browsers and operating systems.
I recommend http://pixlr.com/editor/
It is web-based (so no issue with operating systems) and means that users do not have to download software onto their harddrives. It's also free and doesn't require any registering!
Steps: Simple and easy for users to understand. They should be as basic and short as possible to simplify the process as well as reducing the amount of time it takes to do the process.
- Print screen while viewing your signature.
- Click on the pixlr link.
- On the first menu, choose "Create a new image". On the menu that appears after that, click on "OK".
- Go to "Edit" and then "Paste". Your screenshot will appear.
- On the Marquee tool, outline your signature.
- Look at the dimensions and determine if your signature is a violation or not.