When doing the hem or turn-back I use a suggestion from Barbara Heller and weave several slits across the width of the piece so that the turn-back area won't pull in at the edges. I usually make the slits 3" to 8" across, more or less, depending on the width of the whole piece. On the 19" wide landscape I made two slits at each edge as I wove the 1" wide turn-back (on a larger piece I make that a bit wider):
Above is the piece laid out on the grid board. Weft ends have been trimmed and the piece has been steam pressed (I didn't block* it, just gave it a pressing using steam in the iron and a dampened press cloth on top). The turn-backs were finger pressed down and T-pinned, then steam pressed and left overnight.
Next, I basted the turn-back using regular sewing thread and a big running stitch, removing the T-pins as I did that:
Once
both sides were basted, I stitched down the turn-back using a tapestry needle and a tiny stitch
that caught only a little of the weft at the back of the tapestry.
Since this piece will be mounted onto a fabric covered board I don't
need the turn-back tacked down more than that.
Finished turn-backs on both top and bottom; I've trimmed the warp ends a bit more and left them about 3/4" long:
Soon I'll post about the next finishing steps for this piece. It will be much like what I've shown before when I've mounted small tapestries on a fabric covered board as described in this post.
*Kathy Spoering wrote a great post about blocking at her blog--find it at this link. I don't always block tapestries but when I do I use her suggestions.