One way to construct a stitched double weave
Many years ago, I sampled for a stitched dw - it had a kind of point twill for the background, and a fairly open layer of (I don't remember... both pictures and draft got lost in a computer upgrade, and the physical samples are in A Good Place somewhere... There were a couple of cushion made, and then sold.)
So I tried to reconstruct it. I used 16 shafts on the AVL, so some of the tries I just did have too many treadles. This, therefore, is simpler: a 10 shaft point threading and treadling for the bottom, and a plain weave for the top.
I decided on a ratio of 3 (bottom) : 1 (top).
Here is how I started:
The red square is what the bottom layer looks like; the blue rectangles show the plain weave. These layers are now totally separate.
I started to add stitchers. Below is one way of doing that - I'm sure others can come up with "better" ways...
The red marks show where the top layer weft is stitched down to the bottom layer (by raising some warps); the blue marks show where the top warp is stitched to the bottom layer (by lowering the top warp under a bottom layer weft).
When looking at the back, it becomes obvious that I wasn't as consistent as I thought... (but I'm not going to weave it, anyway). The general idea is to place the stitchers so that they will "disturb" the top layer as little as possible - therefore they are placed near the places where the top end/pick is going under the top pick/end. Ideally, the bottom layer warp will slide over the stitching points, making the reverse side look undisturbed. To facilitate this, I would use a reed which is good for sleying 3/dent for the bottom layer, then sley 3 bottom + 1 top per dent.
(Click pictures to biggify)