Ignore partial post above... I clicked "Submit" too soon...
Unfortunately for what you want, Visio is working as designed -- you can control whether you see the grid when editing or printing, but Visio is "helping" you by removing it when you save in other formats (e.g., the grid is not saved when you "save as web page" either).
I can think of two alternatives to get grid lines into an image:
- Print to PDF, then convert the PDF to an image. Although this is two steps, it will work. There are a lot of free and paid PDF creation and manipulation tools available if you don't already have one; I happen to use a free utility called PDFill that does both things. Question: can you use a PDF instead of an image? Then you'll get the grid lines in just one step.
- Create a simple grid with Visio and either a) put it on a background page that you can apply to any page you'd like, or b) put it on a Visio layer. If you do the latter, you can set the layer properties to "invisible" and "print" so you'll see your homemade grid in the printed output but not on the screen.
Regards,
Scott