Getting the borders you want on Tableau tables can be a very tricky business. When you're building your views and trying to get the borders in place it can feel like you're in a Wonderland, where nothing is what it seems, and nothing stays the same.
The fundamental source of perplexity is that Tableau's borders model is not intuitive, and it's operational model of configuring the borders further muddies the water. In combination, these make for a situation where getting what you want is very much a trial and error process, made worse because it's an unstable condition, and almost not repeatable.
By unstable we mean that the borders configuration you specify can be changed by Tableau in response to actions that are not, from our perspective, connected to the borders' configuration. The Tableau Public workbook embedded below illustrates the basics of this—as dimensions and measures are added to a worksheet Tableau changes the table's borders on its own. This is at best confusing, and is a signal that Tableau considers border decorating an implicit property of the visualization process. In this concept, Tableau reserves the right to change the borders at will, with the user's border specification a subordinate consideration.
In order to get the borders you want, follow these steps:
- content first: fully construct your table with the rows, columns, and contents you want
- style second: configure the borders to your satisfaction
- accept that if you change the rows, columns or contents Tableau may well reconfigure the borders