I've been knocking my head against these same questions again lately. I've heard this pattern selection advice forever but I still don't know what to make of it. It really comes down to knowing too little about the pattern makers assumptions. Done correctly, the shoulder fit should be changing quite slowly with the grade, so picking by a measure more closely tied to shoulder is possibly isolating and amplifying the least significant data the pattern provides.
One thing that I was slow to appreciate, is the base pattern really should be two darts. One for shoulder to bust. One for bust to waist. Yes, by manipulation they can be combined, but you loose information and it muddies the fact that there are two corrections to make. Basic drafts, and grading schemes use the two dart block as fundamental.
I've been thinking more about the base pattern being 2 darts of shoulder and waist rather side seam and waist. Originally I was focused on what was more of a neutral position with the center of the dart on either horizontal or vertical grain for deriving other styles from the base pattern. However I think you are correct in that having the shoulder and waist darts allows one to see how various body aspects are integrated for fitting purposes
With two darts the bust level can be held on the cross grain. Still some ambiguity whether this is a horizontal level in 3D space when worn, unlikely. But having both a horizontal and vertical base line is key. Draping methods start here, and then form the corrective darts above and bellow. Drafting methods do the same. Plot the maximum width then plan waist suppression and shoulder separately. (Actually Helen Joseph Armstrong is an exception here. Her bodice draft creates one dart bellow the bust. I need to look at it again. The other strangeness, it requires a shoulder-slope measurement from shoulder point to center front waist. Then on that line, plots bust depth which was taken from HPS not shoulder shoulder point. Similar numbers perhaps, but why?) Grading methods, again, the coordinate system is key, so establishing that is the goal. The grading book I've been reading is by Taylor and Shoben. There's not that much text, but I think it is nicely theoretical. Most books aren't at all. It uses two-dart bodice pieces, and neutral is shoulder darts rotated to the neck, waist darts balanced on the grain. The one thing about grading, it's basically altering area without upsetting the pattern contours to the full extent possible. So pick a zero point, and specify adjustments a single cartesian system (e.g. grain and cross grain). Sewists fixate on the seams.
"Done correctly, the shoulder fit should be changing quite slowly with the grade" yes exactly so it is the grading also the impact of the height used for the base size as the shoulder length will be proportionate which results in slightly too much distance for individuals with average height (5ft 4in for women).
Interesting thought about the base pattern, I was thinking that with the side seam and waistline dart .both darts can have balanced grain which is more of a neutral starting point.
I'm waiting with bated breath for the next article, Ruth!!
I've been knocking my head against these same questions again lately. I've heard this pattern selection advice forever but I still don't know what to make of it. It really comes down to knowing too little about the pattern makers assumptions. Done correctly, the shoulder fit should be changing quite slowly with the grade, so picking by a measure more closely tied to shoulder is possibly isolating and amplifying the least significant data the pattern provides.
One thing that I was slow to appreciate, is the base pattern really should be two darts. One for shoulder to bust. One for bust to waist. Yes, by manipulation they can be combined, but you loose information and it muddies the fact that there are two corrections to make. Basic drafts, and grading schemes use the two dart block as fundamental.
I've been thinking more about the base pattern being 2 darts of shoulder and waist rather side seam and waist. Originally I was focused on what was more of a neutral position with the center of the dart on either horizontal or vertical grain for deriving other styles from the base pattern. However I think you are correct in that having the shoulder and waist darts allows one to see how various body aspects are integrated for fitting purposes
With two darts the bust level can be held on the cross grain. Still some ambiguity whether this is a horizontal level in 3D space when worn, unlikely. But having both a horizontal and vertical base line is key. Draping methods start here, and then form the corrective darts above and bellow. Drafting methods do the same. Plot the maximum width then plan waist suppression and shoulder separately. (Actually Helen Joseph Armstrong is an exception here. Her bodice draft creates one dart bellow the bust. I need to look at it again. The other strangeness, it requires a shoulder-slope measurement from shoulder point to center front waist. Then on that line, plots bust depth which was taken from HPS not shoulder shoulder point. Similar numbers perhaps, but why?) Grading methods, again, the coordinate system is key, so establishing that is the goal. The grading book I've been reading is by Taylor and Shoben. There's not that much text, but I think it is nicely theoretical. Most books aren't at all. It uses two-dart bodice pieces, and neutral is shoulder darts rotated to the neck, waist darts balanced on the grain. The one thing about grading, it's basically altering area without upsetting the pattern contours to the full extent possible. So pick a zero point, and specify adjustments a single cartesian system (e.g. grain and cross grain). Sewists fixate on the seams.
"Done correctly, the shoulder fit should be changing quite slowly with the grade" yes exactly so it is the grading also the impact of the height used for the base size as the shoulder length will be proportionate which results in slightly too much distance for individuals with average height (5ft 4in for women).
Interesting thought about the base pattern, I was thinking that with the side seam and waistline dart .both darts can have balanced grain which is more of a neutral starting point.