Earlier quoted context omitted.
> "I need a frame that has a 18x18" opening," That's just the poster size that you enter in, right? https://www.levleframes.com/frames/new?height=12.0&width=12.... I punched in 12"x12" and it's showing me various frame/matte combinations that result in a 12"x12" opening.
No, punching in 12x12 gives you a 13x13" frame: Customizing a frame to fit a 12.0" x 12.0" print 13 x 13 x 0.75" Black Maple frame with No mat and Standard glaze. $43.50 I'm saying that my matted print is 12x12 (or whatever), and I don't want to futz with making the numbers come out right.
Maybe I just misunderstand how frames are described and sold, but I would fully expect to receive a frame with a 12x12" opening ("to fit a 12.0" x 12.0" print") if I bought that frame, and would feel misled if I ended up with a 13x13" opening. Again, maybe that's just how frames are sold, but if that's the case perhaps the site could explain that better.