When I start making patterns for the costumes, I usually don't have any idea of the trims that may be used or the button size that may be chosen but those things make a huge difference in the final pattern and in the making up process of the costume.
With our footmen costumes, the shape of the wide trim and the placement of the trims dictated the amount of button stand and the spacing of the buttons as well as the construction technique to a degree.
I first fit the waistcoat by pinning it together along the CF line so I have a true line to go by once the trim is decided.
After the designer pins the trim in place, I have to work everything out for the stitchers.
(I also need to make sure that there is adequate support behind the trim so if I haven't cut enough support at the beginning I have to add more later. Luckily I had cut it in the first place.)
So I need a map of sorts.
I made a small sample of the front, and went to the buttonhole machine to put in some holes so I could determine the smallest hole size I could use. I wanted the wide trim to cover the tail end of the buttonholes, and I also wanted the button spacing to work out so that there was a buttonhole at every curve of the wide trim.
I needed to allow just enough space in front of the buttonhole to accomodate the narrow trim.
Once I had all of that figured out, I could mark the garment properly for sewing.
Armed with the map, the seamstress did a preliminary lay-out of the trim, so we could make sure it worked for button placement and also to figure out how the best way and place to turn the corner with the trim as it travels around the skirt and neckline of the waistcoat. This preliminary work allows us to sew most of the trim on by machine which is usually the most efficient way of applying it.
The right front is not a problem in that the trim could go on by machine before the facing and lining were installed. The difficulty with trims and functional buttonholes is that the buttonhole machine does not take kindly to trim, so we had to be clever and put the trim on around the skirt of the waistcoat by machine and then stop just below the bottom buttonhole. The buttonholes have to go through the facing, so the facing was put on and basted to the inside, then I put in the buttonholes. After that, the trim was basted in place, covering the buttonhole ends and then handsewn to the fronts. The facing and lining seam was then joined by machine and the waistcoat front was finished as usual.
It is interesting how many details need to be thought out in order to finish a garment. More than most people would realize, don't you think?