Saturday, July 25, 2015

49: SAFETY-STITCH SEAM PROBLEMS

Whether or not you sew, knowing something about sewing makes one a better shopper. This post is about why it's important to take a look at the seams when trying on clothing in the stores. The post discusses safety-stitching, how/why it is used to manufacture garments, and problems that one might encounter in garments made with this method of construction.


Safety-stitching sews the seams
and finishes the edges in one operation.
If the seams breaks, the overcast edge will prevent the
garment from opening, which is why it is called a
safety-stitch.

Below is some information about how safety-stitch seams are sewn. Safety-stitching is a very fast way to sew seams as seams are both sewn and overlocked in one operation. These machines make it possible for industry to sew garments, such as t-shirts, together in 5 minutes or less. An advantage of safety-stitching is that if the seam breaks, the overcast edge will prevent the garment from opening, hence the name safety-stitch.

Safety-stitching is a good choice when sewing bias garments because the stitching has considerable recoverable stretch. But safety-stitching is much more often used to produce garments that are best described as cheap. 

Although operators overseas have tremendous hand-skills and can sew at the speed of lightening, they must sew as they are told. Manufacturers want to make as large a profit as possible. Here in the USA we pay top-dollar, often for inferior products. These products are made by overseas operators who get paid very little to produce garments that are often very poorly made. Everyone looses.

When one discovers that a sewn garment has flaws it needs to be returned to the store. The store then returns the garment to the factory, as this is the factory's problem. It is important that we return inferior products. If we accept inferior products that is what the factories will make. 


1: Lockstitch sewing machines have bobbins.

1: Lockstitching is produced by sewing machines that have bobbins (diagram 1).

Lay people usually call lockstitching straight stitching, Straight stitching is a term that can be applied to a number of straight stitch types, the reason the industry uses the term lockstitching.

2: Overlock sewing machines have loopers.
Home sewers call overlock machines sergers.
2: Overcasting and chain stitching are produced by overlock sewing machines that have loopers (diagram 2).

3: Safety-stitching with a lockstitched seam. 
Safety-stitch machines sew the seam, while 
simultaneously overcasting the edge of the 
seam This is a good choice when sewing woven
fabrics, but not when used to sew knits as it is 
unlikely that the lockstitched seam will have 
as much stretch as the knit fabric, and therefore
the lockstitched seam may break fairly easily.
4: Safety-stitching with
 a chain seam, the better choice 
when sewing knit fabrics


3. Safety-stitch machines sew the seam, while simultaneously overcast the edge of the seam (diagrams 3 and 4).

4. Some safety-stitch machines sew the seam with a lockstitch. These machines have a bobbin  (diagram 1) that interacts with the machine’s needle as the seam is sewn. They also have a looper  (diagram 2) which interacts with a second needle to simultaneously overcast the edge of the seam (diagram 3).

Safety-stitch machines that sew their seams with lockstitching are a good choice for sewing woven fabric at top speed. But they are a poor choice when used to sew knits. The lockstitched seam will not stretch with the knit fabric, often causing the seam's thread to break.

Chain stitching requires slightly more thread than lockstitching. That is why manufacturers may try to save a little money by sewing knits with these machines. The little bit of thread saved adds up when multiplied by a thousand garments.

5. Other safety-stitch machines sew the seam with a chain stitch. These machines have a looper that interacts with the machine’s needle  as the seam is sewn. They also have a looper which interacts with a second needle to simultaneously overcast the edge of the seam. These machines are a good choice for sewing knit fabric because both the chain stitching and the overcasting provide stretch. The stitching is compatible with knit fabric (diagram 4).


e-mail

Phone: 215 884 7065

© Laurel Hoffmann, 2015. All rights reserved.
All material on this blog is copyrighted by and is the exclusive right of Laurel Hoffmann.

Sunday, July 19, 2015

48: WHY I WRITE

Knowing industrial pattern making 
and sewing enables one to make 
clothing that may otherwise be
unobtainable. Here my children 
pose in their brother/sister sailor suits. 

Industrial sewing can be done on very basic machinery.
Treadles made clothing manufacturing possible.  




I thought it would take about a year to write what I knew.
After approximately 25 years I'm almost finished.  :-))
It was just as well that I didn't know what I was getting into.

Years ago, having retired from production pattern making to raise my children, I decided that the pattern making and sewing methods used in designing departments should be available for laypeople to learn and use.

Contrary to popular opinion, Industrial sewing can be done on very basic machinery, it can even be done on a treadle.  In fact it was the invention of the treadle sewing machine
that made it possible to move clothing manufacturing into the factories.




Treadle sewing machines 
made both anti-bellum
gowns and manufactured 
clothing possible. Sewing
could now be produced
within a reasonable 
ime frame.
One can date when the treadle sewing machine was invented as it was then that anti-bellum gowns became fashionable, gowns that involved yards and yards of sewn fabric, advertising the affluence of a woman’s husband.

When I entered the industry I was stunned to learn how differently the industry sewed. The methods used in industry were so much easier and much more reliable. As I learned pattern making and grading, needed for my job, I made sure to also learn the sample making procedures. I wanted to be able to sew professional clothing or my family and myself at home like that made in the designing departments. I asked the sample makers how they sewed. Although not allowed to sew on the machines while on the clock (I was management, not union so therefore was not allowed to sew on the machines), I practiced at lunch and at home.

Once retired to raise my children, I began sewing at home. I bought home sewing patterns to speed the drafting, using the same drafting procedures to set up the purchased patterns that I had used in the industry, as rarely are industrial patterns drafted from scratch. Most patterns used in the industry are modifications of previous patterns for garments that have sold well the previous year. Before I had gone into the industry I had made clothing using those instructions. But only about one in three garments were ever really successful. No wonder. The instructions were awful! I decided to rewrite them. I figured it would take me about a year.

One book turned into six, then seven, now eight, with spin-off booklets.
New covers are planned for some of the books. In the meantime others are being copy-edited.
So far three are on the market.
I write everyday.
What keeps me going? My students' enthusiasm. 



When Philadelphia University asked if I would like to teach in
Continuing Professional Education it gave me a chance to
develop my program. My adult students told me what they
needed. They were terrific.

Maybe it was just as well I didn’t know what I was getting into. I"ve been writing for approximately 25 years now.

For the last several years I've
been renting space and teaching
at our local Catholic church.
But my students prefer private lessons. 
So I'm now teaching out of my home.
I never thought the one book I had decided to write would turn into books, a publishing company, years of teaching in college while developing a graduate level program, or in having my own school. Once I moved over from the degree program to teaching in Continuing Professional Education I was free to write and teach, using my own methods. My adult students asked for what they needed, enabling me to learn what was needed in the books,and how the books needed to be written.

Christine grades her patterns to her fit. Knowing how to
correct and grade home sewing patterns speeds the work.
Success! Christine tries on her jacket's
muslin. Understanding grading
enables Christine to eliminate hours
of fitting. 
 My goal was to produce  heavily illustrated picture books that would take a layperson step-by-step through the process of drafting and sewing that would enable her to correct her patterns to her personal fit, and then use the easier industrial sample making procedures to produce professional garments; clothing that would not beg the question, Did you make it?

Rotating each bisection begins
the process of drafting a princess seam.

A true bust dart, drafted
to the true bust point, is bisected.
I hoped to eliminate all writing – I wanted to have just pictures in the book. But I found I had to add writing as my students also needed written explanation. However, the emphasis continues to be on the visual, as most people who sew learn from the graphics, reading the captions and copy only to clarify the diagrams.

Having worked in couture, I like to
 in
clude  high-end  instructions,
just in case a student might want
to set matched bound buttonholes.




In the industry seamstresses who set zippers set 500 a day. This illustration shows the first step. Once learned one needs
no pins at all
 to set this, a lapped, hand-pricked zipper in 5 minutes or less. And it sets perfectly every time, closing the seam right on the seam's sewing lines.

Why isn’t this information already on the market?
Here are four of the reasons this information isn't available:

1. Most of the people who do the sewing in the industry are not college educated. Those who become sample makers (seamstresses who can sew an entire garment together using the sewing procedures that will be used to make the garment when it goes into mass-production) have risen up through the factory ranks, learning industrial procedures step-by-step until they know the whole process. They are then promoted into the designing department where they sew the sample garments as those garments will be sewn on the factory floor, checking for problems as they sew the garments together. Although intelligent, because they do not have college degrees they rarely, if ever, are hired to teach in college. They also rarely have the skills, or the opportunity to write down the sewing methods they have learned in industry. This is the fundamental reason the sewing books on the market present home sewing.

2. Few people, including the editors at publishing houses, know how industrial sewing done. This is unfortunate as there are many people who might be able to manufacture small runs of sewn products in their home and sell them in local stores or on the net. There’s no way anyone can be truly successful with sewn product manufacturing if they don’t have industrial skills. Home sewing methods just take too long and too often produce less than professional results.

3. Because pattern making has a symbiotic relationship with sewing, patter nmaking skills have to be included with the sewing instructions. Pattern making requires good fitting skills. In other words, books that give the information that is needed are difficult to write and illustrate. As I have found out, it takes years and requires classroom testing to be sure the information is accurate and can be understood.

4. Before the computer it was impossible within a reasonable time frame to diagram and write this material so that lay people could understand it. Just one of my books would have taken a life-time to complete.

5. The home sewing books sell. Publishers prefer to publish books that have a guaranteed market.


Here are some of the problems caused by lack of access to this information:

1. Industry doesn’t know where to find the trained workers it needs.

2. Many people who are highly proficient at home sewing might like jobs in the industry, but unfortunately they need to be retrained if they are to be hired. Home sewing procedures can NOT be used in the industry.

3. Because factory workers are specialized, few are cross-trained. When the factory system left the USA, most of the factory seamstresses didn’t have the pattern making skills they needed that would have enabled them to start manufacturing small lots in their homes.

4. And it is a problem for young girls. Industrial sewing and pattern making is low level engineering. Learning industrial sewing is an excellent preparation for a future in engineering.

5. Because home sewing is taught in many, if not most fashion training programs, students are often unable to get jobs in the fashion industry.
   
Knowing how to produce professional garments is fun.

Why learn industrial patternmaking and sewing?
Knowing how to produce professional garments is fun.


e-mail

 Phone: 215 884 7065


© Laurel Hoffmann, 2015. All rights reserved.
All material on this blog is copyrighted by and is the exclusive right of Laurel Hoffmann.