Here's the situation: (First-- I can't supply any photos-- I did say in my posting that I can't put my hands on the cord I need to link the camera and the laptop. Hopefully there are some folks here who can visualize and help.) The 11x14 photos are in frames. But they are proving to be a bear to hang. They are acrylic frames with 4 tiny super-strong magnets embedded in the acrylic, in the corners, that are held in place by 4 more super-tiny magnets in the backing board. (Crate & Barrel has larger versions on its website--I had actually purchased 2 of those but then realized they had sawtooth hangers, and I really didn't think those were proper for the weight of the acrylic). My goal was to align them horizontally, with three 5x7s in between them. BUT: The frames have sawtooth hangers on the back. And I've realized that not only are the frames themselves not all the exact same size (by the tiniest of measurements, but still), but also, the positioning of the sawtooth hangers is not consistent. I have tried measuring and remeasuring. I have tried the method in which you lay it out with paper templates, mark on the paper where the hanger is, tape them up and hammer the nail on the mark. I've even tried that "Hang and Level" plastic tool -- which is terrible for aligning multiple items, because the picture hangs too far out the wall when you attach it to the tool. I bought the frames several years ago when Aaron Brothers was in my area, and it never occurred to me to make sure they were the exact same size! Also, I think that I've discovered that the ceiling line and the corner wall line themselves are not completely straight (at least, when you put a bubble level up). What looks OK close up looks "off" from 10 feet away. It's incredibly frustrating, but I still love the frames and want the photos up! That's why I thought the ledge(s) or glass shelves would work better for me. And they'd allow me to put a few other smaller framed photos on them, too. I'm going to take a deep breath and measure again and give it another try. In the meantime, what's your opinion on the ledges or shelves?

Ikea has those exact shelves. I have them for spice shelves in the kitchen. Used them in another house to display framed photos, where I could change them often.

they should be hung around this height You could do taller pieces there too. I also think that tile should stop at crown level and the crown should be straight across. the way you currently have it, run into the ceiling, makes it look abnormally tall and out of proportion. If you had taller ceilings I think you could get away with it. tried to find similar fireplaces I did find this one w/out the crown, but it's a taller ceiling and there is a drop ceiling over that portion. however, notice the art pieces on either side and how tall they are

I have done a lot of gallery walls over the years. Most were at our homes, but a couple in DD2's homes. One of hers and two of mine I measured area to be covered, then (sometimes) mark the corners of this area on the floor with painters tape. I also just lay out the tape measure (seen below) I then laid out the art inside the area. Once I knew which pieces I was going to hang, I cut brown paper to each size. For the master bathroom (below, in our last home), I used a pencil to write the measurments on each piece and assigned a number (also written on the back, and on the brown paper cut out). Then I started in a corner and used painters tape to hold paper in place. Once I was ready to start making holes, I went directly through the paper. If there aren't too many to hang, and in a secondary space (like laundry room), I will just eyeball it as I go. Then I start hanging and hold my breath. I wanted to add two tiny pieces top left, but I could not work the ladder around the wall and tub to reach that high.