For my eco printing, I search thrift shops for natural fiber shirts that are in good condition. This is a silk shirt in a size 6.
 
I used a variety of flowers such as pansies, coreopsis, and geraniums. The tag says to dry clean, but it should be handwashed in cool water with a neutral soap, rinsed, rolled in a towel and then hung to dry. 
 
Over time the prints will fade some, but with care, they should last for many wearings.