Outstanding response, Paul, thank you.
Just got back from Hobby Lobby and bought a pack of 25 Crystal Clear bags in the 13x19 size. Package claims the bags to be acid-free, and cost $10.99. Seemed like a good deal. My Premier Art paper comes in the 13x19 size, and the bag is actually a bit larger so's to accomodate the paper. That's the paper size I use for prints in the 11x14 range. I've just treated them with Printshield and will let them dry overnight, as you suggested.
Now if the print in the Crystal Clear bag fits the box the paper came in I'll be golden. We'll see. The longest the print will be in the envelope (and maybe a box) will probably be in the half day range. I was glad to hear the carbon ink we use produces such a dry print.
Stay tuned,
Paul W.