During our wedding process we have tried to keep our paper and printing usage to a minimum. I am an advocate of using paper as a communication medium, but just think we should do it efficiently and in an eco-friendly manner if you can... for all aspects of our lives. For us this has included using recycled paper products for our save-the-dates with ink and pen writing (the magnet wasn't so kind I admit), sending out a double-sided tri-fold brochure that also acted as an envelope for our newsletter update, and planning to recycle the paper for the invite and potentially using silkscreen for the type. There are far better craftier people that are experts in material usage and how to maximize design for efficiency out there and I found one great resource through treehugger recently.
Monadnock Paper Mills has released a Field Guide for Eco-Friendly, Effective and Efficient Print that is available as a .pdf from their website. The 38-page book is also available in print. It is a cool little guide with sections on paper, production, inks, printing, finishing, packaging and reference information. Here is a small excerpt:
The purpose of this guide is to offer information in support of sustainable design and print. The message is threefold: Eco-friendly design can be cost-efficient, environmentally sensitive and beautiful. This guide gives graphic professionals the opportunity to think about design differently.
The purpose is aimed for professionals but the text of the book will not be over anyone's heads. I have seen some truly atrocious paper projects that people have sent out for their weddings during my own planning process. Looking at the final product I have thought in my head, "why didn't you just send an e-vite and not waste all that paper?" I admit a lot of my bias is based on the lack of optimal design (efficiency).
I think this book can serve as a good guide for brides that don't want to go as extreme as my save-the-dates (minus the magnet ;)) but still send out a nice presentation. Since I am by no means an expert in all things print I have learned a little bit about printing alternatives already by simply glancing though this guide once. For example alternatives to petroleum based inks include a suite of agri-inks besides soy ink and there is even a recycled ink option. The packaging section has tips for minimizing your material use and designing a presentation that can save you money in the long run.
Take a look at this guide. It is free and you can download it. Oh yeah, their graphics are pretty as well.