FULL COLOR PRINTING; ONLINE
PsPrint
Lately I’ve been going here the most. Their special pricing is amazing, and the quality is great. I’ve had enough experience with this one that I actually opt out of the Proof options all-together with confidence. 
With their ultra-competitive offers, I’ve been able to produce custom pieces like this graduation announcement that would have cost me twice as much anywhere else (like Kinkos). This example is just a simple 5 x 7 on cover stock. My quick photo doesn’t do the actual printing quality justice.
Just for staying with me here, here’s a direct promo code for 20% Off Your Next Print Job at PsPrint
(enter “SALE” at checkout)
OvernightPrints.com
is one I’ve used with confidence for years. Very affordable pricing, relatively fast turnaround (in the end you’re really at the mercy of your chosen shipping option), and consistent quality. I use OvernightPrints.com for my some own personal printing and even used a spot varnish on my last business card without paying a fortune for it.
PAPER SOURCE
More than just commercial paper products here. Paper Source is the premiere paper store for envelopes and handmade paper products from around the world, with collections of Japanese paper, Lokta and Indian printed papers, and are continuing to add more and more papers with high recycled content.
One of my favorite things relating to printing is Letterpress. In addition to a beautiful selection of finished letterpress products, Paper Source also has a great selection of materials for your own Letterpress Machine.
In addition to papers, I especially like this 
Desk Embosser & Custom Embosser Plate
, something I use on my own art giclee prints to give them an added level of authenticity. I’ve shopped for totally-custom embossers before – having one 100% custom from my own design/signature is crazy-expensive. These at least give you some presets that are fine-tuned to chose from.
Aside from actual products, paper companies and suppliers, in general, can be really great sources of creative inspiration. Check out Paper Source’s Do Something Creative Every Day ®
