On the previous backsplash I did I just used a 4" tall tile with a bullnose edge. I wasn't happy with the finished result because the whole backsplash just looked too thin.
For this backsplash I'm using tile cut to 4" tall, but capping it with a pencil trim all the way around.
At the corners I'm cutting the pencil trim to 45 degree angles. The gap between the vertical and horizontal surfaces will be filled with caulk.
To create the little gap I'm looking for and to keep the tiles from sliding down the wall I taped some washers in place. A benefit from having done so much metal fabrication work is that I've got a good selection of hardware like this in various sizes and thicknesses.
