Fitting the Garment
When fitting the pattern, follow these suggestions:
Carefully cut a slit for the throat down the center to allow some comfort and breathing. Do not cut too low, as this is only a temporary slit. The neckline will be shaped and cut out later.
Place the pattern into position around the person, seams facing out. Hold the shoulder area in place and pin the shoulder seam. Pull up enough extra fabric for a seam allowance in the shoulder and try to pull the tops of the gores up fairly close to the armpit. There should be a slight slope at the shoulder and a wing like excess at the arm side of the seam. Make the neck slit longer if necessary. It is important to get the shoulders right at the beginning. Letting the shoulder seam in and out will change the rest of the garment since it will rise and fall on your body from this point.
Start with the front seams, pinch and pin the pattern to establish the bust line. For bustier women, it may be necessary to pull out the basting and reposition the first seam a little higher and/ or deeper. This is because there is a natural inclination of the seam to have a pucker here. In a modern pattern this would become a dart. Since it is not an option in this garment (this was not common period practice), it must be incorporated into the fit through the seam.
It is a good idea to pin down to the waist, or wherever seems to allow the best beginning of the drape of the skirt. Then work on the back panels, and go as far down the back as the top of the hips without being too tight. Most women do not like to have their back sides emphasized, but do like to have a shapely figure. The fit also needs to be loose enough to walk, sit, and function comfortably. Don't take in too much on these seams. Remember you have all the ones under the arms too. Spread the fitting over all the seams.
The middle seams are next. The remaining seams between the front and back one are done at the same time, to keep things in balance. Pinch the excess fabric and pin the shaped seam in place. There should be a slight flair from the bra line up to the underarm. This is fine, remember that the gores will be shaped to resemble a cola bottle. When all of the seams are completed, mark the new seams with a pencil, or disappearing pen while the person is still in the muslin. Then take out all the pins, both at the side and at the shoulder, and remove the dress.
With a different coloured pencil, redraw the lines to make them even. This is to ensure that the seams do not lose the shaping you pinned so carefully. Sew the marked areas. If there is a lot of excess, trim the seams.
When completed, help the person back into the garment, leave the seams on the inside. Without the distraction of the excess fabric, it is easier to see if there are any puckers, gaps or problems. If any appear, pin them out, you can transfer the markings later. This tends to be trial and error at this point, so relax and work with it. Check the shoulders first, then the body seams. This is the time to take the bra off to fine tune the fit if a supportive garment is desired.
When everything else is fitting well, move on to the armholes. The armhole should be high up under the armpit, and fit closely around the arm and shoulder. Move the arm up and down, forward and back. If there is a lot of fabric in the way, remove it, but remember to leave seam allowance. Drawing the shape on to the fabric may help. Also making small clips into the fabric, perpendicular to the edge can help with fitting, without removing cloth.
Draw the neckline on the fabric. This could be one, or many drawn at different levels. If this is to be a master pattern, keep it small and close to the neck, you can always make it bigger.