Pattern for the sleeve - I measured the length of the armhole and drew this. It's just the shape of the armhole as it will look like from the side, then you take the lower half of it and mark the place where the sleeve would (or wouldn't) be joined together. This will split the lower half in two parts which then will be mirrored vertically (outwards).
I pleated a reversible rectangle I'd made. The pleats go in one direction. I pinned them, then I transferred the shape of the pattern and adjusted the pins to lay both above and below the curve.
I sewed the pleats and cut the unnecessary fabric. Then I could pinn the sleeve to the armhole and find out how it fitted (of course I did it before sewing as well, but you can imagine how precise pinning a bunch of double velvet is).
What would you expect? Yes, it didn't fit. Somehow I got the curve a lot longer than the one of the armhole. After some time spent on trying and experimenting I cut the right part of the sleeve you saw above. I had to sew the right side which you can see below together (this is much easier when you can do it from the wrong side, reverse and finish from the right side).
When I had two pieces I could sew them inside. I expected the velvet to be more obedient when basted but it wasn't at all. The dark brown was going towards me so at the end of sewing there were nasty wrinkles. Fortunately, it wasn't so visible when I put the basting aside.
I wanted the gardecorps to have a hood, but my boyfriend's birthday party's tonight. I've been working most of yesterday and night only on the sleeves. That's why I just sewed the neckline together and unbasted it. The hood may be inserted someday but I'll hand it on without it now.
Tomorrow I'll give you photos of the gardecorps done. By the way, I couldn't have posted about this before for him not to see it. So if you want to, you can look at the previous cloak posts now, here and here.
