the one thing about old linens is that the the corners are rarely right angles. sometimes you don't notice how skewed the pieces are until you try to frame them or hang them up. still... i like to retain that character. there are 4 layers on this one and although i originally lined up one side to match the others don't come out straight. my solution to this is usually to keep placing the piece on another fabric that is torn on the grain to square up the over all frame. and this rotating idea helps also... to draw the eye away from the imperfection.
in any case, i cut one of the corners off and then put it back so it would line up better. i used a cross stitch to mend it back, in keeping with something traditional i took an extra stitch to tie down the intersection over the break line.... still ragged but held in place.
because the center is woven and then applied to these thin linens, even with cutting the extra layers from the back , the corners were still way thinner than the rest of the piece. i applied patches to the back, just to cover the corners and give them more body. i also used this extra fabric to square up the final piece, letting it hang over to straighten the square where needed, it is a bit darker and leads the eye.
i like the peek at another grid and the extra cloth allowed me to drag the projected lines into the edge with quilting.
and the bonus is there is another revolution on the back caused by many corners coming together,