In continuation of yesterday’s introduction, I think it is important to stress that too many notches is a cognitive shortcut. However unfair, one is going to presume a pattern such that we sampled was made by an inexperienced practitioner and will require closer scrutiny. What goes unsaid is that the more important issue of new patterns is that the seam lines weren’t walked because this isn’t something that is stressed in school. I went to a decent school but I didn’t learn how to walk my patterns until I started working. Production pattern making isn’t what people think; anyone can learn to do it (there is a whole chapter on it in my book). It is probably better described as pattern checking. There are related links at close.
The problem with doing an exercise like this is that you always walk the seam before you sew it -actually, it should have been done prior to cutting- so I walked just the princess seam -that being enough since this style was already a problem. Below is a double pane showing the results. On the left, the pieces are laid side by side and I think we can agree that the seam lengths look pretty good, so good one would be tempted to not even check it
On the right side of the pane you can see not checking would have been to one’s detriment because the seam is a full 1/4″ off; the center front is longer along the seam line. My my.
And in case you wonder, I can confirm that in spite of this being a two piece front, it is a flat piece with no shaping that has been cut down the middle so it is easy to overlay the two edges and get an accurate seam (as seen in the right pane above). As this is a child’s pattern, this isn’t as tragic as it would be for an adult. Still, I’ve often wondered why one bothered to split the piece if there was no shaping -unless the panels were different fabrications. Otherwise, it seems wasteful, extra costs to sew, extra costs to cut, extra costs to grade and bundle -what’s the point? But I digress.
At right is the result of the first seaming. As we discussed yesterday, the seam allowance notches along the vertical princess seam at the shoulder and waist are lost. Kinda. As I’ll show you, those notches -artifacts really- have the potential to create problems all their own. It’s no different than detritus in your shop or home. Leaving something laying out in the open isn’t hurting anything but the clutter is an eye sore and someone can trip and fall over it. I suppose you could think of it as 5S-ing your blueprints.
Moving along, one needs to add the lower waist segment, the first step being to ____ ___ ______. Yes, walk your pattern. Gold stars for everyone! And once we do this we see something a bit disconcerting. by this I mean that the waist seam of the upper bodice had allowance notches but the waist seam of the lower bodice does not. See what I mean by cognitive shortcut?
Doing this properly, you lay the seam lines together as they would lay when being sewn. In this image (click through, it’s not shown) you can see that the lower bodice is also 1/4″ too large to join the upper bodice.
In a production environment, people will give this a fair shake in that they’ll walk a seam or three but if every seam they’ve checked is a mis-match, they’ll throw in the towel. This pattern has other issues -too large seam allowances for one. Who uses 1/2″ seam allowance in a neckline?
Okay, so let us move on to the problems those useless notches cause. First up is the shoulder line (above right). How is one to sew this? Aligning to the shoulder seam notch stuck in the princess seam leads to a catty wonky seam so that is obviously not a solution; it must be angled which raises the spectre of Esther’s comment yesterday that excessive notching can lead to seam bursting (seam failure).
Below, we have a visual of the waist seam before sewing with a two-pane comparison of the sewn seam at upper left. The right side of the inset pane is a magnitude larger, sorry about that. I hope it isn’t too confusing but I did want to get a close up of the stitch line.
The ruler shows that the waist seam was sewn at 1/2″ as required but the seam is missing the mark of the intended waist seam allowance notches that were stuck into the princess line.
At right in the above photo, you can see the CF edge of the upper bodice waist seam is shaped rather oddly. The CF seam at the waist needs to be squared off a minimum of 1″ on either side of the overlap which is actually closer to 2″.
To me this says the pattern maker wasn’t sure what to do -and I feel for them because they have little guidance. It’s not like it was when we were coming up. Many of us had supervisors or other pattern makers on the job that we could ask (sometimes futilely but that’s another story). Anyway, the patternmaker remembers -correctly- from pattern class that a properly fitted bodice pattern actually curves up at the CF waist. However, this garment is not fitted, there is no curvature in the princess seam and the piece being flat, should not have a curve at the CF waist. Compounding the problem, this is for little kids. Little kids have bellies so if anything, the bottom of the CF upper bodice should be longer, curving down, not bowing up.
I suppose the above and what I’ll show next is beyond the scope of this post, not particularly dealing with notches but it does reinforce the cognitive shortcut that excessive notching is indicative of other problems (if it quacks like a duck, walks like a duck…) so it would be good to go out of your way to avoid being taken for a duck and refrain from being notch-happy.
The lower bodice looked off so I laid an L-square on it and this isn’t going to hang evenly horizontal at the center front hem. This would be okay if the style was meant to hike in front but it wasn’t intended to do that. The hiking at CF would be compounded by the horizontal seam at the waist. When you have a suit coat type front hem finish with facing and you want it straight on a large bellied body (also applies to expectant mothers), you have to add curvature and length at a horizontal waist seam if it is available.
In sum, this pattern is a train wreck. Now I’m going to tell you the rest of the story. This was a home sewing pattern. The designer didn’t want me to know she was using home patterns so she hired a design student to put it on oaktag, modifying the seams to 1/2″ (because that’s what “everybody” does now) and mark it properly or at least, as well as the student knew to do (she did forget armhole notches for sure). The student wasn’t supposed to make pattern corrections -who knows if she could have, it would have been a lot of work and require advanced skills. All told, this was not fair to the student so don’t do this to an intern if you have one. Someone else might not have known the back story and would have thought the student was grossly incompetent. And not that the designer told me, I figured it out.
Production pattern making class
Tip for checking your patterns
How on earth do you use oak tag to MAKE patterns?
Paper patterns, soft or hard?
How to walk a pattern (video)
How to walk a pattern pt.2
Poka Yoke pattern making
How to walk a collar