Originally Posted by
bearisgray
Maybe draw out the back with the "finished" measurements - and then add the seam allowances on?
See attached drawing.
Assumptions: that the dimensions given are for the size of the top right now
that you want the borders to be 2.5 inch
I would cut the center piece 58 x 11-1/2
Thank you! I was doodling all over a paper with dots representing inches, etc. I think in the future I'll stick to solid backgrounds.

And yes, actually cutting the borders to 3" would help because they could be trimmed down afterwards if necessary. I just happened to have some 2 1/2" strips I wanted to use up for this but in the future, I will plan on 3". Then if my middle piece is off, I can take it from the borders as necessary.
Thank you!