Diversified plain weave

I've been experimenting with diversified plain weave for a project.  This is the first sample so there have been many since then.  I put on some waste thread to see how my pattern was developing and to see if I understood what I was doing.  I had read as much as I could find in Handwoven magazines, books, on line lists but my biggest problem was figuring the ratio of thickness of yarn to sett in reed.  This, while looking as I wanted it, is far too heavy for a garment collar.
Warp:  cotton, centre part thick and thin (it gave me an idea of coverage), outside edges cotton
Weft:  one thread cream cotton, several gold lurex.
One thick, two thin threads per dent 12 dent reed.
I tried spreading the warp out to the equivalent of three threads per dent in a ten dent reed which was a nicer feel but the gaps didn't close up so the pattern was compromised.
The experiments continue.