I left about 3" of a seam open which was enough to turn the bag inside out so the stitched seam was inside and then whip stitched the opening once I was done filling the bags. Will post pics of that for you though.
And I'd be happy to post templates once I find them. The wife rearranged her sewing bench (which I had confiscated for my projects the other day without asking her permission) and my templates are currently M.I.A. lol
I think that the texture change was the outside edge of the fabric, I think their machine was off kilter or something that day because the other bolts of canvas I have had have never had that on the edges of them.