With sublimation, one of the key tricks to creating your graphics for two-sided objects (large or small format) is making sure the product lines up. The quickest and easiest way is to reverse the first image or graphic keeping the text and copy out as they will reverse and no longer be legible.
Another option with all-over sublimation for large-format T-shirt printing is to keep your design out of the trouble zones such as the armpit and upper shoulder area. With this in mind, create your design to flow from the bottom up, either by fading a gradient toward the top or having a pattern that works with the trouble zones.
-Sarah Young, Coastal Business Supplies