Supporting your local custom framing shops is the fastest way to get the exact look you are going for, but because custom framing isn't exactly feasible for everyone, here is a quick sourcing guide that should help get your prints on the wall faster.
What is most important to you when looking for a frame?
Real glass over Plexi all day long
If real glass is a must, some of the larger NNTC print sizes will no longer be an option. Poster frames are typically found with a glass alternative which makes them much lighter. If you are looking to have a larger print framed and are unable to be swayed by the benefits of Plexi, then you may be a candidate for custom framing.
Otherwise, we're big fans of OUI frames. OUI products can be found at Indigo. All glass-compatible NNTC sizes are linked below.
Can deal with Plexi, but it's gotta be real wood
In that case, there's this other company that we love called Opposite Wall. Canadian-owned and based out of Montreal, their frames, poster hangers and art shelves are made from FSC certified wood and cover the full range of NNTC sizes. They are minimal with a mid-century feel and come in light, dark, black and white solid oak.
5x7, 8x10, 11x11, 11x14, 12x12, 12x16
16x16, 20x20, 16x20, 18x24, 19.75x27.5, 24x36
Don't have a preference either way as long as there's matting
If you want to choose your own matting (at an additional cost), then Opposite Wall is your best bet. Otherwise, OUI frames come pre-assembled and ready to go.
Other places you can find frames
HomeSense has a variety of real glass frames to choose from and is an incredibly convenient stop for planning gallery walls.
Ikea is perhaps the most cost-effective option for framing, but they have 100% made the switch from glass to Plexi with no signs of going back and operate in pretty obscure print sizes.
Now, whether you're someone who likes to have a frame sourced and ready to go or someone who is always going to get the art up soon, check out NNTC prints and make it so!