BGG user panicz1982 asked if there was a board frame, and I could not find one. Therefore, I made one.
https://boardgamegeek.com/thread/3517418/is-there-a-frame-that-goes-over-the-board

Board dimensions are simple: Frame is 195mmx195mmx5mm outside, board hole is 191mm, Play area is 187mm. This grid should still fit within the box. It does in mine from 2016.

You might notice that the play area is larger than the printed play area grid which measures 180mm. Truth is the pieces don’t actually fit within the printed area! In this case, I found a measurement that worked for even the most generous arrangements by fitting as many single row pieces and patches together so the bottom face (sharp corner) was aligned across the board and expanding the play area to fit this new width.

Print it upside down to prevent having to use supports.

Blog detailing process: https://www.danlearnsstuff.com/2025/06/patchwork-board-overlay-workflow-and.html