My board mounted paintings are some of my favorites because they're ready to hang as soon as you get them home. It's also a nice, modern way to display my watercolor art. They take quite a few extra steps to get them ready to display and sell though!
Watercolor reactivates if it gets wet, so the very first step is to spray the painting with varnish to seal and set it. Then I use acrylic medium to "glue" the painting to the cradled board. Next, I put heavy weight (usually a giant stack of books!) on top of it overnight to ensure a clean adhesion.
Once I have the paintings mounted on the cradled board, I trim the excess paper away from the board edges for a nice, clean look, like I show in this time lapse video.
I didn’t get these edges trimmed as neatly as I’d like, so next I sanded them down. Then I move on to the final part: 2 coats of wax finish and a buff out ensure a lovely matte finish.