Crown molding. I guess I should have done a better job listing the products and prices.
I got a "propak" of the crown molding, which was very affordably priced at a little over $1/ft for 60'. I also bought 4 premade inside corner blocks (which come oversized, as an accent). The total bill was actually like $90. For once.
The reason I bought the corner blocks was because I knew it was going to be a nightmare to correctly compound miter the crown molding. I am borrowing that saw from Bryan so the problem is not that I can't make a compound miter cut. The issue is different molding actually sits on the wall at different angles, which is called the spring angle. For example, some sits at a 45° angle. This molding does not. Because of that, you have to use these translation tables.
http://www.compoundmiter.com/chart.html
While it WOULD have been fun and a challenge, I decided the corner blocks (much like my rosette choice) would just make life easier. Turns out my walls, in the corners, are all wider than 90° somehow (which means the walls must all bow outward before coming back in at the edges). I could also have just coped the joints rather than worry about a miter. Never tried that and this didn't seem like a good time to learn.
By the way, my measurements rounded up to about 62 linear feet, so I hoped that with the rounding and the extra ~3-3/4 inches the corner blocks gave me that I'd have enough material. Turns out I have several feet leftover.
Here's what the cross section looks like on the wall.
The order went something like this:
1. Start with a whole piece, cut to length for the office side wall
2. Use a whole 12' piece uncut for the kitchen side wall, closer to the fireplace
3. Take a third whole piece, cut to around 5' and that would be the fireplace wall, closer to the front. This would give me a seam about between the recessed lights above the fireplace
4. Take the rest of that third piece (about 7') and run from that corner to where the middle curtain hanger is, which seemed like a fine place for another seam
5. Take the fourth piece and cut for the remainder of the front wall
6. Take the fifth piece and cut for the remainder of the fireplace wall, and remainder of the kitchen side wall
The key is managing the seams (plan where they go). I didn't end up with any more than 1 seam per wall, and the office side wall has no seams. Well, obviously there are seams at each corner block.
Speaking of, here's a corner block.
And another.
Office side wall with a single piece and the two corner blocks nailed up.
That mantle sure needs to be painted white. These were made from a single 12' piece.
And this is an uncut piece.
A completed corner block and molding.
Ugly gap because the walls aren't 90° (or straight).
That was the first round. I filled the holes, wiped them off, and went for round two.