Our wood block polo shirts are really unique and probably the best use of our library of vector artwork.
The polo shirts are our best selling products and outsell the traditional dye sub shirt by a factor of 8 to 1. You can see both of them at http://www.delphic.com/boeingb52.html . The design is a large collage of the same elements as in the t-shirts and mugs but are without the fills. I first created line drawings of the B-52 elements for both shirts. I then added gradient fills to one version of the drawing and arranged the elements in a collage in another version. The polo shirt brings in much more revenue dispite the fact that it is significantly easier to draw. I expect the same results with my next project, the Essex Aircraft Carrier (http://www.delphic.com/essex-class-aircraft-carrier-polo-shirt.html) .
We are considering licensing other people's vector artwork for our polo shirt business. If you think that you have artwork that would look great on a polo shirt, please e-mail me.