For the new shirts I propose these layouts:
(klick on the image to see the large version)

front:
front full view, frontside, about 119kB
front full view, frontside, about 185kB
front full view, frontside, about 153kB
front full view, frontside, about 124kB
back:
front full view, backside, about 53kB
front full view, backside, about 15kB

The old layout is as follows: Here are the pictures I took from my nethack shirt. As said on the special page, they are sold out.

On this overview page I have only put the small previews, if you click on the picture, you'll get the whole image.

full front full view, frontside
about 80kB
detail front detail view, frontside
about 150kB
full back full view, backside
about 35kB
detail back detail view, backside
about 125kB