This is from a company called Composite Projects, their work focuses mainly on environmental ethics and health issues. Their piece to the left, The Environment, Who Cares? focuses on the environmental issues designers come across, the resolution it's self handles this using only water based inks and 100% post consumer content paper, that is also process chlorine free.
thomas.matthews handles his design for print in a similar manner, making sure that his work is printed on only 100% recycled paper and that the inks that the printers use are soy based. On a side note, apparently finding an environmentally friendly printer is quite easy, most newer printers have started this way, seeing the environmentally friendly element as a viable selling point in this modern climate. Though for older printers it's expensive to convert and there is no legislation asking them to change.
I chose to look at this company (IDress Myself) because their quite small but very successful. All their products are hand screen-printed, not just t-shirts, but posters and other products too. This means that they can chose their inks and avoid wasting left over inks, where a printer may have to throw away a one off "spot colour" after it's used because it takes up unnecessary space and may not be cost effective to store for the amount of time it's used. On top of this, they happen to be great designers. :).
Here's some links to good websites.