So I’m going merrily along sewing up my sample of the back vent for the tutorial series and get to this point:
and find I have a serious problem. Oh my. How embarrassing. You may not know what the problem is here but the end of the stitching on the green piece is supposed to end relative (aligned) to the seam on the red piece -and it’s not; it’s off about an inch. Still, I always knew there’d be a problem with a tutorial at some point, I just didn’t know when. Regardless, I’d decided a long time ago what I would do when an error in a tutorial happened and had decided to use the experience -when it reared its ugly head- as a lesson in troubleshooting. As a result, this portion of the nameless tutorial has necessarily become an exercise in troubleshooting. I’ll bet a troubleshooting tutorial has you so excited you can barely sit straight. I’ll bet you’re just giggling with glee. Well, I won’t keep it from you any longer, read on.
First of all, this never would have happened to you in real life because you’d never cut a pattern without walking the pieces together first, would you? [nod your heads gravely in agreement] I didn’t think so. Still, in spite of the best of intentions, mistakes happen. In most sewing factories when something like this happens, it seems the goal is to find whoever is guilty of the infraction in order to inflict blame and/or abuse…but that’s the wrong goal. While you do need to know where the problem originated, you also need to know what went wrong with your system that the problem was allowed to enter the process stream with such a defect. Your system can be designed from the outset to prevent problems. Troubleshooting just doesn’t mean solving problems productively, it means problem prevention too. Anyway, you can only start at the point when the problem first became apparent and track it backwards from there to correct it at the source.
In order to track it backwards, let’s follow my process. First I laid out the lining patterns. I don’t like pinning so I sprayed embroidery adhesive to the backs of the paper pattern.
Below you can see the dots are marked. So far so good.
Below I’ve laid the linings right sides together and marked the dot intersection with a pin.
Below I’ve sewn to the first dot.
Below I’ve clipped the inside corner (to the dot) and am preparing to pivot the top piece into position.
Here you’ll see I’ve placed a pin at the second dot and aligned the seam.
Below, I’ve completed the seam, stopping at the dot and back stitching. By the way, dots always mean “stop”. The first dot I stopped and pivoted while this second dot indicated the end of the seam.
Below I’ve joined the shell and linings together (I’d already done that small L shaped seam of the shell center back to the top of the vent). As in the first tutorial, the lining and the hem is joined first.
Below I’m finishing off the shell portion of the lower edge of the back vent. Please note that I stopped stitching 3/8 shy from the cut edge. If you over-stitch this, just undo that last little bit.
Then, I clipped that corner.
and rotated the piece to sew the lining to the vent’s cut edge
but then, (below) you’ll see (or maybe you won’t) we have a problem. The last dot of the lining CB seam is supposed to meet the top of the vent’s CB seam but there’s a gap. A fairly large one too, about an inch.
Before I go any further, maybe I should explain acceptable tolerances. A gap of an inch is not tolerable. A gap of 1/8″ is tolerable provided it’s a pattern the company has been sewing and using for a long time. In other words, the stitchers remember the gap is there before they ever pick up the piece and adjust accordingly. Personally, I find 1/8″ to be absolutely intolerable; my personal standard is within 1/32″-1/64″. If it were my company and there was a problem of 1/8″, I’d have it corrected because these things can snowball because it’s standard practice to trace off one style to create another and why introduce an unnecessary defect into the next style? Still, as I said, there are cases when the company won’t want to correct a mistake because the correction is seen as more costly than the error. I do not agree but that’s just my opinion. If it were a leather die and it meant remaking dies, well maybe it wouldn’t be cost effective but otherwise, it would be.
Another thing…many times the designer (you) has hired somebody to make their patterns, and as is often the case, the pattern maker will try to downplay the importance of the problem because it’s work they have to fix and they won’t get paid for it (if they’re not your employee). I say too bad because this sort of error was preventable (later) and they would have caught the error if they’d checked their work. They’re responsible for checking their work before passing it off to anybody else in the process, period! If a pattern maker has to remake patterns to correct mistakes on their dime, they’ll either begin to check their work as they should be doing anyway or they’ll become a designer (joke). Typically, a good pattern maker will be aghast at their error and correct it once it’s brought to their attention. A less than professional pattern maker will minimize the significance to avoid the re-work. That’s one way to tell who’s a good pattern maker.
Anyway back to the sample. Once this problem is discovered, everything should come to a screeching halt. Do not proceed further. Now is when trouble shooting begins. To troubleshoot, work backwards. This means you’d check each of the previous seams first, have they been sewn as directed? In this case they were. Okay, since sewing isn’t the problem (it never is; while poorly formed seams may be apparent, the cause necessitating the sewing work-around started well before then) you go back to cutting. Was the cutting a problem? In this case, it was not. The pieces were affixed with adhesive, the drill holes were marked and all cut lines were cut away. Therefore, this leaves the pattern as the likely problem (this is nearly always the problem).
So let’s troubleshoot the pattern next. Below you’ll see the Left back shell and the Left back lining pieces. These are the pieces I was sewing when the problem first became apparent. First, I’ve marked off all seam allowances on both and folded the fold lines.
Below you can see I’ve folded the back shell onto itself in the positions it would lie were it sewn.
Below you can see I’ve repeated the process for the back lining.
Below, you can see I’ve laid the two on top of each other and a quick glance may not show the error but do recall that the lining is not supposed to be flush with the end of the shell hem!
Rather, the lining should be shorter. Below I’ve pulled the lining up into it’s correct position. It’s readily apparent that the problem here is a too-long lining.
The correction (below) is simple. It’s precisely one inch too long. I’ve marked it off, cut the difference away and folded the seam allowance.
And here -finally- you can see the lining reset into position with the correction and it matches perfectly.
When troubleshooting, you should use these same steps to find problems and correct them. Don’t skip a step in the process because it may not be your pattern but the cutting. Or, it could be that the wrong pattern entirely was used. I’ve actually seen that happen. To troubleshoot that, you take the leftover pieces of the marker and lay that on top of the hard copy pattern. Sometimes the person who made the marker grabbed the wrong parent style or used an earlier version of the style. That’s another reason you need a good style numbering system. I should write about that sometime. Briefly, if two items “look” exactly the same except one takes buttons and the other takes a zipper, they need two entirely different style numbers because the patterns are different. Using different style numbers even tho the two styles “look” the same would prevent these kinds of things from occurring. Style numbers don’t number/label styles so the name is a misnomer. Style numbers number/label patterns! I realize home sewing is different and you get one style number for one envelope of different patterns but this is not home sewing. And, if it doesn’t work in home sewing (and it doesn’t) there’s no way it’d work in industry. By the way, you can walk your home sewing patterns just like this and you will be absolutely amazed at how bad they are! They don’t check their work.
Speaking of not checking your work, it is unlikely that this specific error would have occurred in real life. Not by a professional anyway. A professional would have compared (walked) the side seams of the front and back linings and found the disparity well beforehand. It is imperative that someone, either you, the pattern maker or a sample maker to walk the pattern before a sample is ever cut out. And you can see why now. On Monday, I have to start all over again! You don’t have to though. To make your corrections, cut one inch off your lining pieces and you’re good to go. You can do this tutorial this weekend.
Related:
Name this tutorial
Nameless tutorial #2
Nameless tutorial #3
Nameless tutorial #4
Nameless #5 (back vent)
Nameless #6 -Troubleshooting
Nameless Tutorial #7
Nameless Tutorial #8
Nameless Tutorial #9
Bravo! This reminds me of an experience I once had…… One of my professors had us each choose a vintage design, create a more modern version of it, then pattern it. Always wanting to challenge myself, I designed a dress that became the greatest challenge of my college career. I won’t go into the details of the design, but suffice it to say, my time was up and I had spent hours grappling with this pattern and sewing multiple mock-ups, only to be left with a very sad and unsuccessful (or so I thought….it wasn’t “perfect”) final project. I presented my dress to my professor feeling defeated and quite the failure. I made an A+. My professor told me I had learned more with that one project than I could have possibly learned with a succesful first try. Since then, I have looked at my mistakes in a whole different way. They are productive. I have the utmost respect for anyone that can admit their mistakes.
okay, lots of questions/comments:
1) if I came up with the answer “the lining is too long,” I would assume that it was supposed to be folded over (most bagged hems Ive seen seem to be…), and rather than cut an inch off, I’d put a notch or two in to show it folding. I suppose you could check ths by comparing this lining piece with the one it’s supposed to attach to. If they line up, I’d suspect the fold more than an overly long lining….
2) I still use tracing paper to make my patterns because I couldn’t for the life of me figure out how to walk oak tag. (did I mention I’m totally untrained?) I mean, with tracing paper, you can see through it to overlap the seamlines. So do you really fold the seam allowances back on every pattern? Is that accurate enough (that stuff is hard to fold! for me, anyway…)? Doesn’t it make your pattern a mess?
3) I just read “the machine that changed the world,” and it’s fun to see you applying some lean logic to your posts. But a question that’s been bugging me while I read the book bugs me even more now. If you don’t run a factory, but subcontract, how can you expect the sewers to be looking for mistakes and trying to make improvements??
Jinger –
Re: “How can you expect [subcontractors] to be looking for mistakes and trying to make improvements?”
Womack and Jones’ follow-up book, Lean Thinking, addresses this problem in detail.
You have to get all links in the chain talking frequently and easily with each other. It’s difficult, and there will be active resistance and finger-pointing to offset blame. And fear that breaching confidentiality will weaken one’s bargaining position, blah blah blah.
Remember how it was so difficult for Toyota to implement these changes in Post-WWII Japan that Ohno’s uncle had to apologize publicly and resign as head of the company?
We can learn how others managed to surmount these obstacles (and perhaps as important, the mistakes that lead to others’ failures).
Re: Jinjer 2)
Make your oak tag working master after you’ve made a prototype pattern and test-sewn it.
You can see that Kathleen is using paper in this tutorial. I like physician’s exam table paper, as it’s considerably cheaper than tracing paper (even student-grade architectural rolls) and won’t give paper cuts.
You can walk any pattern by sticking pins through the sewing lines, even on oak tag. Something light enough to see through is easier.