Don't glue the design. The glue could damage the fabric, in time.
If possible, use acid free card, cut the the fabric the design is stitched on larger then the board, then lace it at the back, with strong thread or dental floss, nice and tight so it is stretched evenly over the board. Then frame it.
Herring bone stitching Suzette - its sewing as though laceing a shoe if that makes sense lol
If you type in google .... How to herringbone stitch I'm sure it would have some direction - good luck
Karma
I wish I could help you I have only framed a couple of small ones and I embroidered on stiff cross stich fabric and just framed it I am sorry,