Process review: lapped zipper

Posted by Kathleen Fasanella on May 17, 2005 at 4:15 pm / Lean Manufacturing, Quality, Tutorial / Trackback

Shown are the inside center back zipper insertions of two different dresses from the same manufacturer. This manufacturer was of considerable size, importing their styles into the US from a Chinese contractor to the tune of 100 million dollars in sales in the late 90′s.


While I don’t know all of the company’s problems, the company was sued by Merril Lynch for over 11 million in unpaid loans. If you have two identical closures -regardless of styling- they should be sewn exactly the same way. If you can’t reproduce these kinds of basic garment features with uniformity, it means you don’t know what to do or how to do it and nobody should be lending you money. The closures should look more like this:


The first problem is that all styles that carry this sort of lapped zipper application should all be sewn exactly the same way regardless of who’s sewing it. I know that a lot of people new to the business may find this alarming but there really is only one way to sew this correctly (which I’ll prove with the demonstration of the correction). The first concept to grasp is that all seam edges should line up evenly. For example, the left seam allowance sticking out from under the zipper should be even with the zipper tape and these aren’t. In other words, company A wasn’t a product focused company. These sorts of glaring problems would have been corrected after the first prototype in a pull manufacturing company if it even got that far. Still, company A couldn’t have listened to what their chinese contractors had to say about the pattern, otherwise it would have been corrected. How can a company ignore 100 million dollars worth of product with the same error? That’s why I wouldn’t have lent them any money. This is a common example seen in push manufacturers. Their focus is low product development and production costs in order to pay for higher marketing costs and scheduled mark-downs, many as soon as they hit the sales floor.

I’m sure that company A provided specifications, they had to have provided specs for a lapped zipper- otherwise the contractor would have sewn the zipper centered with a double lap because that’s how the pattern was made. The facing is another story; it was made like the ones seen in home sewing patterns so there was no way it was going to sew up correctly. In other words, while the specs called for a lapped zipper, the pattern was cut for a centered one. A centered zipper is most typical of CAD pattern templates because a centered zip set-up is what’s called a 2-per or mirrored piece (read: easy) that costs less in product development, fabrics, marker making and marking itself (there’s no difference in sewing cost). It wouldn’t appear that this company did much more than print out the template (I’ll refrain from a discussion of the fit of these garments). The evidence is clear.

A little zipper say can say a lot. It tells me that
1. The contractor is not to blame for this pattern (or the product quality in spite of the fact that they sewed it). They couldn’t figure out how to do it which is why these are sewn two different ways- and the fact that it could have been two different contractors (there’s no way of knowing), it shows that neither contractor could make the zipper work in accordance with the pattern and the specifications for a lapped zipper. The contractor had to ask for a correction (either provided by company A or executed in-house) because it was costing them a lot more money to sew it the wrong way (forced by the poorly cut pattern) than it would have cost them to sew it the right way. Doing things right the first time always costs less. Below is a view of what the zipper looks like from the outside (the green and blue dresses are the same; the color difference is due to photo editing)


Company A did not review the product quality beyond external passing-glance appearance. If product quality had been a priority, this insertion would have been corrected. The lesson for DEs is to develop standards, cut your patterns to match the standards and use the same configuration in every other applicable style. It’s a good thing to develop standard practices. You sew each given zipper type exactly the same way regardless of in which style it appears. In other words, all lapped, dress-weight, neckline zippers are drafted and sewn exactly the same way between styles. Not only should these zippers be sewn this way in this company but they should sewn way in every company because there is only one way to do it correctly. I’ll show that next.

The seam allowance on the left is too wide and check out the width of the facing seam allowance!

The seam allowance to the right is too narrow. I can’t even imagine what the defect rate must have been due to that mistake.


Of the two, the pink sample was worst. The zipper is on top of the facing!


I’m sorry but I just can’t respect somebody who puts out something like this. I don’t care this was a 100 million dollar company, they were amateurs in production. Companies like this are just riddled with waste and need off-shore margins just to stay afloat.

Process review: lapped zipper
Lapped zipper template
Lapped zipper construction
Lapped zipper specs
Centered zipper template
Centered zipper construction
Invisible zipper tutorial pt.1
Invisible zipper tutorial pt.2
Shorten a separating zipper
Zippered welt pocket tutorial
Deconstructing a zippered pouch
Zippered welt pockets

15 Responses to “Process review: lapped zipper”

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Jess Latham
May 18th, 2005
4:04 PM

This is one of the big problems we are having in the learning process. I’m always afraid I’m going to sew something the wrong way. In your book you mention a lot about “sewing gurus” that claim to know “industrial techniques” and I’m always wondering if the books I have are leading me in the wrong direction. Do you have any sewing books that you reccomend? I do a lot of reverse engineering and now I’m spooked about that cause what if they’re wrong too? hehe.

May 19th, 2005
4:49 PM

Regardless of the supply or lack of edu-sewing materials currently available, reverse-engineering is absolutely the best way to figure out how to do things. I mean, that’s how I learned it! If you look in pattern books, there’s no clear -or as the case may be- correct instruction regarding specs of seam allowances for different effects like zippers etc. For some reason, they always include how to draft the sleeve vent of men’s dress shirts but not much else. I didn’t learn to do all of this stuff in school either. I learned most of this stuff via reverse engineering. As a matter of fact, that’s pretty much how ANY manufacturer has done it too. Consider reverse-engineering a time-honored tradition in every field of human creation and manufacturing because it is. There are no books that I use but I do love vintage sewing and tailoring books.

Once I post the template patterns for this lapped application and include the photo instructions (step by step), I’m hoping that people will actually do the exercises. I’d really like to write a sewing/patterns book and I’m hoping participation and feedback will be enthusiastic enough to show me that there’s sufficient demand for a book like that. But, if I don’t get participation and feedback, it’d be silly to move forward on a huge project like that.

May 19th, 2005
4:56 PM

oops. Re: reverse engineering. I neglected to mention the previous posting I’d made on this topic. The post was made Feb 17, 2005 and it’s called _thrift store shopping_. Paste that title in the search box on the main page and it’ll take you right there. This post gives guidelines to using reverse engineering.

Jess Latham
May 19th, 2005
7:55 PM

The only book that I have that is pretty good is Sewing for the Apparel Industry by Claire Shaeffer. I’m not sure how correct this book is. One thing I noticed is the way it explains to do a single or double welt pocket. Using strips of fabric but I reversed engineered a pair of pants with a welt and found another way where the welts come from folding the fabric and that was much easier for me. I think this is what you were explaining on your website somewhere, simulating a Reese machine. I’m working on an experiment of my own. Ok, my theory is that bar tacking instead of making a stronger garment actually weakens the fabric. During our last family get together my brother in law was talking about how his pants were always falling apart on the back pockets and on the belt loops and then I noticed that one of my belt loops was actually broken. This made me start thinking about why this happens. Poor thread? Does the fact that there’s a bump (folded fabric) on the fabric surface cause extra wear in that area? Is the bar tacker needle actually weakening the fabric? Something to ponder!

May 20th, 2005
10:14 PM

This is the 3rd part of the 4-part series regarding the process review of the lapped zipper. The first entry analyed the correct application of a lapped zipper. The 2nd part was the pattern templates needed to execute the proper…

May 21st, 2005
1:15 PM

About C. Shaeffer…I should send her a thank you; she’s provided me with more impetus to correct erroneous information than any other home-sewing “expert”. If there were a singular source to my rant in the entry of 2-22-05 (the cognitive dissonance of experts), it’d be she. She is the author mentioned regarding the designer Claude Montana btw. You mention her welt pocket method…that’s only one thing she’s perpetuated (repetitious material present in any given sewing book from the fifties onward). In spite of her many assertions to the contrary, she’s never worked in the apparel industry. I wouldn’t consider teaching sewing at a community college out in Palm Springs CA to be “industrial” experience.

In my entry also of 2-22-05 _nothing pithy here_, I quoted Eric (elevated from comments under cognitive dissonance entry)
….”Therefore, the ancientness of the apparel industry lends itself to secrecy and mysticism, and therefore may be exploited by anyone claiming to have unlocked these secrets. If it’s not in the open, anyone can lay claim to having the knowledge. Nobody in the industry is likely to come out from behind closed doors to dispute them, and nobody in the general public knows enough about it to dispute them.”…

This comment inspired me to get serious about transparency and putting everything out in the open -just what do you think this blog is about? Shaeffer can only claim to have unlocked our secrets because we have let her. Well, I’ve come out from behind closed doors to dispute her.

Honestly before, the hobbyist press was just a cause for laughter-a way of amusing ourselves if one happened to see them. The industry was robust and we were swamped with work so who cared what was printed in a college textbook? But the costs of our isolation increased as trends changed. With the field narrowing, any information that sifted through that funnel became increasingly influential. Note that I said influential, not accurate. It became an issue when -through the fallout- the largest publishers came to dominate the market, when previously the garment industry had always had a significant insider’s trade press consisting of pattern makers and plant managers who had taken the time to write some of this stuff up. The books weren’t pretty but they reflected the needs of the daily reality of people working in plants. In other words, due to the shift in trends, the information market narrowed to favor textbooks written by people who marketed themselves well and knew professional book proposal standards that publishers wanted to see. I resent this narrowing of information resources because we can’t afford it like we could before (as though we really could have afforded it then). We have fewer resources and less ability to weather the consequences of our poor decision making that is based on poor information. These costs are utterly wasteful because no value is generated.

This industry has become so fragile and still more fragmented, an ugly self-perpetuating cycle we’re finding difficult to reverse. Fragmentation drives our fragility when we can least afford it. For example, as the larger plants closed, people stopped attending the annual trip to mecca (the Bobbin Show in Atlanta GA). Once things got really bad, the show’s sponsor ceased hosting it annually. While no one disputes the wisdom of that decision in the economics of terms favorable to the largest companies, it reduced the rate of opportunity for peer to peer information transmission which hurt the smaller companies most. Now we have almost no opportunities to share information peer to peer, making it less likely we’ll meet someone who could resolve some basic problems. Failing to have a venue for meeting has dramatically increased the value and costs of good information.

Now, as the opportunity to acquire person to person information has been reduced, iinformation has become more rare and costly. The costs are generated when the entrepreneur must learn through the process of trial and error. A side effect of expensive education is that people are less willing to share their information with each other due to the cost of their own investment.

It’s my personal opinion that the costs of bad information are more wasteful and costly than learning by trial and error over the long term. I realize that in the beginning, Shaeffer’s book is useful if you don’t have anything else, so you use those methods to get off the ground. The problem is, those habits become behaviors and once it’s become a behavior, it’s a problem that is harder to break. Once behaviors are institutionalized, people will make all kinds of rationalizations to justify what they’re doing and how they do it. This is the path of least resistance and these kinds of companies don’t last very long. Led by their information resource, they tend to produce products with unnecessarily high costs but lower quality standards. For example, sewing a sleeve lining in by hand is lower quality, not higher. This method is rationalized as “quality” when the reality is, the hand sew method is just a way of compensating for the fact that you don’t know how to bag a jacket professionally. The former is a shoddy work-around and not a quality standard. This is an example of waste -muda- and we can’t afford it.

On the other hand, I think the costs of education from trial and error are much more cost effective over the long haul. And it’s funny how the trial and error process works because it’s very common that you’ll be in the middle of learning to dominate a problem and the answer ends up finding you (when the student is ready, the teacher appears). This kind of education is so effective and becomes self perpetuating if this becomes a behavior. The habit and behavior of proactive improvement creates an enviable standard of excellence. This is the core tenet of lean manufacturing and entrepreneurs who are willing to get their hands dirty can only thrive.

May 21st, 2005
1:42 PM

About bartacking.
I don’t think it’s the bartacking that is the problem as much as it is the disproportionate weights of materials joined at that spot -coupled with the mechanical load owing to movement stressors.

For example you can imagine the belt loop as a tube of 3 layers (after folding) with the end of it tucked under which makes for a total of 6 layers that are bartacked onto _1_ layer. The one layer is of insufficient structural integrity to bear the weight of 6 layers, particularly in an area subject to the stressors of vertical and horizontal expansion, no?

If that doesn’t make sense, consider the belt loop end that is bartacked to the top of the waist band. This 6 layer portion is tacked onto _2_ layers that are only stressed by horizontal expansion. I’m not saying it’s impossible but I’ve never seen an instance when the stress load was relieved by the top end of the belt loop coming loose.

Also, as far as structural integrity is concerned, more stitching is better rather than less. It’s a myth that more stitching makes something fall apart due to needle holes punched in the fabric; it depends more on stress and what it’s sewn to. For example, consider flags, the commercial ones flown outside of buildings. Those flags have hems with 4 or more rows of stitching. You wouldn’t think that something designed to hang there would need that kind of structural integrity but they do. The wind can shred a flag in no time at all if the hems aren’t reinforced.

La BellaDonna
December 15th, 2005
2:20 PM

I’d really like to write a sewing/patterns book and I’m hoping participation and feedback will be enthusiastic enough to show me that there’s sufficient demand for a book like that.

Yes. Please. Please write that book; I will buy it, and recommend it. If you don’t write it, who will? No one, that’s who. And the field will be clogged by people who perpetuate errors.

And now I’m depressed. I paid Good Money (i.e., more than I could afford) for a consigned Valentino suit, not because I can wear it, but because it was beautiful, and I want to “read” how it was done – but the sleeve linings are, in fact, sewn in by hand. I too thought it was one of the hallmarks of a “quality” suit. :(

Jinjer Markley
December 16th, 2005
7:11 PM

when previously the garment industry had always had a significant insider’s trade press consisting of pattern makers and plant managers who had taken the time to write some of this stuff up.

Could you post a list of titles of these resources so that if we happen upon them we can snap them up (like crack fiend after a fix)?

Also, it’s good to hear you say trial and error is better than bad education, it makes me feel better ’cause I spend a LOT of time doing it. The wasteful time that I am currently resenting, is the time I spend staring at the pattern paper thinking “is THIS the right thing to do?” I should get over my fear of doing things incorrectly and acknowledge that some testing (and re-testing) will be necessary until I find a tutor at the appropriate level.

On Couture clothes and hand-sewing. I have altered quite a few couture clothes, and have come up with a few observations:
1) Quality varies wildly.

2) Sometime hand-sewing DOES have a quality purpose–I like the flat, smooth exterior effect when seams are hand-stitched to the underlining. You could do a machine version by blind-hemming the seams to the underlining, but I’ve yet to see that. It also helps gathered skirts to fall from perfectly smooth seams to hand stitch the gathers together (and to the underlining) in the seam allowances. Don’t know how you would replicate that effect by machine. ANyway, the point is, sometimes hand-sewing IS the appropriate engineering tool, IMHO.

3) I think the origin of hand-sewing isn’t for the sake of quality, but for the ability to make changes at the last second. Anyway, I know my clients always want changes at the last second, and remember, couture started out as a form of custom clothing before pret-a-porter came around. Machine sewing everything generally does come out nicer, but often requires that you know the exact finished dimensions ahead of time, which isn’t true in actual “couture.” So I find, for my indecisive customers, hand sewing actually SAVES me time and frustration. This isn’t relevant for RTW. (unless you ship garments half-finished to a store that intends to customize them to the customer. Let me know if you know of a store that does it this way).

Joanie Molnar
October 4th, 2010
7:18 AM

I love the way you explained the lapped zipper. My question, how do you handle a little girl’s jumper that is completely lined, lapped zipper down the back, with no hand-sewing visible on the lining side, much like what you show with the facing. I have seen jumpers/sleeveless dresses that are made with no facing, just complete lining, and no hand stitching. The armholes, neckline are completely finished by machine. The lining has been machine stitched to the zipper tape (the zipper sandwiched between the lining and fashion fabric).

Could I use your instructions, but treat the lining as a facing so that the zipper will be neatly sandwiched between lining and fabric? What do you suggest?

Kelly Dowling
December 5th, 2011
2:58 PM

I am very interested in learning how to make my own patterns.

December 20th, 2011
2:01 AM

While reading your comments re: Shaeffer, I couldn’t help but to wonder – your thoughts re: Adele Margolis?? Would love to hear it. Thanks!

December 21st, 2011
10:16 AM

I don’t know anything about her. Since I tend to collect these, I probably have at least one of her books. The name is familiar so I know I’ve at least thumbed through one. As far as I can tell, she doesn’t claim she worked in industry or is/was guardian of their secrets -a point in her favor.

June 11th, 2012
3:48 AM

Yes – Please do write a book about sewing/patternmaking! I’ve been wishing you would but I didn’t want to impose on your time.

Your posts about collars and and sleeves etc. have made much of what is in my patternmaking books reduntant, and the rest of the information is iffy now.

September 26th, 2012
3:41 AM

I have a office in China and I work for the italian market
what you show here is the example of the meaning to produce here or in place like china…
the first things the client ask is the lower price not possible impossible (before quality assurance on the product … (what is etichs in I don’t know)
so generally the factory has a bad enviroment for sure not all the factory !!! but in anycase are full of young people they also don’t know what is the meaning of sewing … and not time to learn to expensive… I try work in a different way also because I have more than 30 years of experience but is really difficult my prices are too hight for the 90% of the client (we are taking about CENTS or maximum 1/2 DOLLAR) … this is a job need a lot of person and the person they must have a low salary this is the KEY point. Is the first job one country loose when the person are treat as person ….
so what is etichs in this ? absolutely nothing !!! But are the rule of the market and as we know the market is much more important of the person… this (and i don’t think only this …) is a job without space for the Etichs … so the zip is the last problem is the small point of a bigger problem

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