...dammed. I *exactly* know how to make that thing.

I even once had the exact fabric for the 'coat' part (silk velvet, etched in a 'wood' design) in my hands - just not dyed yet but still white.

Plus I know how to dye that silk velvet in the two colors teal / rust, and what material to use to achieve the exact and correct changeant colors for the underdress by dying it. I find it extremely interesting how the shape of the underdress and turtle-neck is achieved by simple and more or less strong ruching of the pleated fabric.

Thoughts & planning on the underdress

I *think* that this underdress - from top to bottom - is made of one single piece of silk/rayon satin or rather: several panels of that fabric which were sewn together at the selvage edges - I *guess* that the material is pleated so much that, if it before had a width of 60 inches, will just be about 20 inches wide after pleating (if it's not completely ruched up, which would even make it much less wide: perhaps 5 inches or so).
Given that this estimate is correct, and from what I see the underdress is fully ruched up at about bust height (as well as around the neck), I would have to join at least 8 pieces of fabric to achieve a 'wearable' bust width of 40 inches. The bottom skirt would be the end of those fabric pieces, and if *that* pleating would then be pulled apart, it would result in a hem width of 480 inches (or a little over 12 meters)...
However, as it's pleated, it seems to be much smaller - from my usual 'calculating the circumfence of a skirt by assuming that the height of the actress is equal to my own and then using Pi', I would guess that this skirt - again, pleated - has a hem circumfence of about 110 inches (or 280cm).
That would make about four times as much material as the skirt is actually wide - this vaguely matches my first calculation of 60-inch-fabric becoming 20 inches wide by pleating it. A length of 70 inch / 180cm for each panel would probably be sufficient, given that the fabric is pre-washed and won't shrink any more.
So I would need eight times that length - totaling in 560 inch / almost 15 meters of pre-washed fabric; resulting in a length of at least 18 meters of 'new' fabric to take the shrinkage into consideration. And that's just the pleated body of the underdress; no sleeves or whatever; not to speak of the silk velvet for the 'coat' part... *groan* - can't I *ever* like a gown that's made from less than 5 yards of fabric...?
The pattern for that gown is so simple that I could well sketch it to a scrap of paper within five minutes....

Thoughts & planning on the overdress / coat

My initial planning and thoughts on the black dots that cover the fabric were different and can be found here; anything else on the following page.

I am of course also scared of doing all the other embroidery on all edges of the gown (though I have an idea how I could fake that, so that I would save myself some work without losing the incredible look of that embroidery).
While at first sight this looks as if someone had sewn on two-tone rattail cord to the fabric, it's instead a *very* narrow zigzag stitch with either one two-tone spun embroidery thread or indeed two different threads, applied over a rattail cord; probably by using a ribbon foot.
This embroidery was clearly applied by machine and just a rough sketching (with probably water removable markers) on the fabric, because left and right side are often different, and while the repeat the motif along the edges is similar, it's never twice the same.
It much reminds me of what was done for Episode II with the 'Senate' gown, just that that was indeed soutache embroidery and this here is thread embroidery with an underlying cord to make it look more raised.
I somehow have the idea that this was done before dying the fabric, with one white rayon and one white silk thread running through the same needle in the machine, over-embroidering a black cord (for shadowing out eventual gaps between the zigzag stitching) to be able to dye this embroidery in colors matching the silk/rayon velvet and the silk/rayon satin the other parts of the gown are made of.
That's very clever - you have to know (if you didn't know it so far) that it is very well possible to dye silk/rayon fabrics absolutely two-tone - given that you have the appropriate dyes, which would be the "Alter Ego" dyes by Dupont.
You can even (for example) pour blue silk dye and red rayon dye into *one* pot, stir them until you have a *purple* dye bath and then add (again, for example) the silk/rayon burnout velvet to be dyed. If you have finished the dye and washed the fabric, you will have silk velvet with a blue backing and red pile - each dye has only dyed the fiber it's made for.
I admit that one has to see this to believe it - I didn't believe it either until I saw it, but ever since I simply love that method.

After finding out that I wouldn't be able to get the silk velvet which I had in mind for this gown, I decided to at least try and take the task to make my own burnout velvet fabric. I have burned out velvet before - and with large patterns, even - but I never tried to produce yardage that would be covered with a tiled, repeating pattern as it's the case with the fabric for that 'coat'.

My first steps started by determining the exact velvet pattern - this can be seen on the next page.

*For anyone who's interested:
Here are my initial thoughts on the black dots in the fabric - before I saw Anna's swatch:

I am not only in panic about having to hand-paint or embroider all those black dots to the silk velvet after dying it.
Those black dots could originally either be painted or be embroidered - to hold some flat lining to the silk velvet. That would be a very clever method to attach it there, as ironing a fusible lining would flatten the pile of the silk velvet as long as it's not washed / tumbled after ironing that on. The black dots were *not* on the fabric originally - they are not evenly spaced and show no repeat, while the 'wood' burnout design of the velvet clearly has a repeat. And silk velvet definitely needs a stiff interfacing to look like *that*, because if it had no interfacing, it would pleat very softly around each and every curve of the undergarment / body.
The theory that the black dots might be embroidered to hold a stiff interlining to the silk velvet is *almost* verified by the fact that the black dots are also under that rattail embroidery - they must have been made either before even cutting the silk velvet or shortly after (though it would be easier to do that before cutting, even with the risk that one would embroider more dots than needed by doing so).