You’ve gotten good advice from both your printers, Biggs and PrintDriver. I like Biggs’s suggestion about a small line, maybe near to the FSC logo, mentioning something about the paper.
Eco-friendly paper isn’t quite as straight-forward as people sometimes assume. Most paper comes from what are essentially tree farms, not virgin forests. Paper is basically a sustainable and renewable agricultural product.
Most paper that commercial printers use already contains recycled content for the simple reason that it’s economical for paper companies to make it. Because there are limits to how many times paper can be recycled and because recycled pulp just isn’t as good and new pulp, there are practical limits to the percentage of recycled content various papers can contain. The paper companies generally push up against those limits.
In addition, the whole process of recycling paper isn’t necessarily as environmentally friendly as people assume.
In other words, the majority of paper used by printers already comes from paper companies with a vested business interest in good, sustainable forestry and recycling.
As PrintDriver mentioned, FSC certification is an indication that the paper originates from a company that uses responsible forestry practices, as opposed to, for example, wood clear-cut from the Amazon rain forest.
Most printers can show you samples of what they have or can get. If you want something that’s FSC-certified and contains as much recycled content as possible, just ask if they have suggestions and samples for you to look at. (I always like to use local printers for these very kinds of reasons.)
There are some specialty papers that use pulp not processed with chlorine bleach or use other environmentally friendly processes in their manufacture or transport, but off-hand, I’m not all that familiar with them. I suspect most are more about niche marketing than they are about genuine environmental friendliness. For example, Neenah’s “Environment” paper line.
A few years ago, it was something of a marketing fad to slap recycle and FSC logos on printed materials. Today it’s become sort of meaningless given that most paper is FSC-certified and contains recycled content.