My preferred way to do what your asking is tile the backsplash so the lip of the tile sits 1 2 to an inch under the trim.
Backsplash tile above kitchen window.
One option is to tile around the window and all the way up to the ceiling like this gorgeous kitchen designed by studio mcgee that you can see more of here.
Wipe off any excess grout with the grout.
The more problematic area is to the right and left of the window casing just not enough room to cut and lay tile not to mention the installer will not be happy.
If you have a boring old backsplash that you want to cover consider updating it with paint instead.
Once the grout is mixed you ll have a limited time to use it.
It s a subtle difference versus simply ending at the window but these little details can make a kitchen feel much more finished.
Apply the grout with the grout float at a 45 degree angle.
Using a damp sponge remove the grout from the face of.
In this kitchen by sagemodern the tile continues all the way to the corner and up to the height of the upper shelves so that from a distance the line of the upper cabinets is unbroken.
This kitchen backsplash idea from martha will take your plain jane white tile backsplash into custom look territory.
See more kitchen backsplash ideas.
Every kitchen is different but often the trickiest spot to figure out where you want your backsplash tile to end is around your kitchen window.
Given that the tile may look more like a stripe across the top of the window.
You certainly could tile above the window up to the ceiling of your valance box.