Embroideryis the art of working raised and ornamental designs in threads with a needle. Polo shirts, hats, jackets, blankets (among other items) have typically been embroidered as a way to embellish an item.
There are various factors to help you decide which medium works best for a project. Here is a basic list for this technique that might help...
You might want to use this method if:
artwork size & number of stitching is reasonable (i.e.-charge is usually by 5k stitches or more)
one or two placements (left chest for shirt, front center for hat, etc.)
the desired finished product requires only what embroidery can offer
you like the look/feel of embroidery on garment
This is a great way to print your garments. For your specific project, there may be a better way for your bottom line, turn-around time and/or product quality.