You are correct that custom shape quality falls off once you get to a certain size. Post a screenshot of what you have, so I can better understand what you are trying to accomplish. Then I can send you in the right direction.
You've reminded me of another sore spot--I'd love to be able to reference images based on fields, and add actions to image objects. It would be nice to have the ability to use field names from the data source universally (seems inconsistent that we can reference them in sheets and actions, but not in image objects and dashboards, etc.)
You may want to vote for related ideas: http://community.tableau.com/ideas/1101 (probably several other ideas related to this topic as well)
Anyway, best of luck.
Edit: Had to change the image slightly, wasn't happy with the graphs (even with names blanked) being up.
Thanks for replying so quickly guys, appreciate it!! Mathew, always good to see ideas entered I voted it up there, be really great to have.
Below is a screen cap of one of the dashboards, it would nest in the US Dashboard section.
So if you wanted to navigate to US Dashboard Trend, then you would ideally be brought to the initial dashboard for that subject area.
The image starts out like this:
but pixelates really badly when sized up in Tableau.
Does that make it clearer Shawn?
Kevin, in the attached I've included two different ways to create quasi-buttons. The one on the left uses a transparent mark (polygon) over a bg image that includes Big Six. The one on the right uses a text mark over a bg image that does NOT include the Big Six. Each has pros/cons. Play with them, add sheets and actions, and see which one you like best. Then ask follow-up Qs if you aren't seeing how I made these.
EDIT: Workbook now attached.
Buttons.twbx 30.7 KB
Thanks Shawn, really helpful!
Both solutions make sense, just a matter of working through which fits better for this case.