I've recently begun utilizing the printing services of Staples. Which, if you've never explored and do a lot of printing not from your home, I recommend checking out.
Now, both Staples and Kinkos have features where you're able to email a document and specify paper preferences and pick up etc.
Now, your mileage may vary as the staff of each location differs wildly and that's as important to this whole process as paper selection is.
For what it's worth, here's my opinion of the two chains in the area
College Park- preferred if you need to be in the store. Big, room to lay project out. Good access to their supplies. Also, will let you use their large format printer. Also, open acess to paper stock (not toal stock, but it's enough)
7th & D NW - Staff helpful, not allowed to touch large format printer, easy metro access (Archives/Navy Memorial)
7th & NY - Best staff in the city. Layout a little confusing. This is my preferred Kinkos location, Metro stop: Convention center or China town. 5 blocks from either. Parking not recommended.
8th & D st. SE (Capitol Hill) This one is kind of a nightmare. Good Metro access, but the staff is ridiculous at best and usually surly. Machines largely undependable.
Saying that, I just made tags for my owls and emailed it in to the Kinkos on D st. SE for pick up. I did call ahead to see if they could be done an hour earlier than the web said they would be available for pick up. The guy on the phone assured me no problem. I arrived at the store and no one knew what I was talking about, still they printed the tags out for me, and I have to say, they look great.
That mostly is because I chose the glossy cover card stock. An option Staples does not have.
Location: Rt. 193 Greenbelt/near college park. Across the street from Beltway plaza mall. It's fine, they're competent. Not my first choice.
Location: 14th St. Columbia Heights- great. Huge, new facility (no room for project layout, but good) helpful staff. Understand double-sided copies.
Kinkos wins for more convenient locations and I think paper selection.
just a tip