CHICAGO, IL — (Marketwired) — 04/09/13 — Two Sides, the fast-growing non-profit organization established to promote the responsible production, use and sustainability of print and paper, today announced that NewPage Corporation has joined the organization."For a company like NewPage, a business whose products come from the forest, sustainability represents a unique opportunity to make a positive difference for our planet," says NewPage Vice President of Marketing Steven Devoe. &quo