Most trim carpenters don t even use a tape to trim windows.
How to install trim corners around windows for vinyl siding.
Install j channels at doors and windows and under roof eaves and rakes.
It s all done by eye with a sharp pencil a miter saw and an 18 gauge nailer.
Along the tops install j channel trim with horizontal siding and base trim with vertical siding.
Instruction on how to install exterior 2x4 trim around a new or old window.
You can use wood trim from the hardware store or some other product.
Cut the trim so it is two channel widths longer than the opening s width.
But in my experience the best product is a vinyl flat trim that matches the window frame.
After the insulation is in place you want to install trim around the inside to finish the job.
Many people myself included are very sensitive to insulation.
When installing window molding start at the top.