I came across this when browsing the D&AD website. This particular series of designs entitled 'Natural Medium', won an award in the field of 'Greetings Card and Invitations' under the category of 'Graphic Design'.
The designs stood out to me due to their uniqueness in being on a dry leaf and I was even more impressed by the concept. To save me explaining it, here is the segment of text which accompanies the images:
"In Cannes Lions 2008, our agency presented the 'Designing Naturally' workshop, which discussed the role of design as a tool to transform the future. For our invitations, we asked our team to select images that, along with the time and date of our workshop, were laser printed on fallen leaves collected from the streets of Rio de Janeiro. Simple, different, meant to be looked at against sunlight – our invitation became a new medium, a flyer that is actually supposed to be thrown away on the ground. Paint free, borrowed from nature for a purpose and then returned to it."
And here are some of the actual designs:
All of the following images can be found at: http://awards.dandad.org/2009/categories/grpd/graphic-design/22803/natural-medium
So that's 'Natural Medium by 'Tátil Design'. A very creative and innovative series of designs which rightfully won a D&AD award!