so, i'm having a pair of jeans made . . . .

[PandaDenim]

Those coffees are dope.

[OMEGA JELLY JIGGLE]

picture book for those too lazy to go through the thread:

edit: SORRY MIZ!

[mizanation]

now there are two ways of attaching the yoke, with two very different consequences.

one way is putting the yoke on the bottom and the pant leg on top of the seam. this is the way levi's does it and most likely, the yoke on your jeans are also sewn like this. this provides the strongest seam.

if you look at your jeans, you will see what i'm talking about. the lip of the seam is facing up.

the other way is to put the yoke on top and the pant leg on bottom. while this is structurally a weaker seam than the one described above, there is one big advantage. you will find this seam on wrangler jeans which were designed for cowboys. when cowboys are on their horses, this seam provides an easier way for them to reach inside their back pockets. if the lip of the seam is pointing upwards--like in levi's--then, oftentimes, people would get their fingers caught on the seam. as well as being inconvenient, constant friction on this ridge would eventually cause tears.

wrangler style yoke:

[mizanation]

we are sticking with a standard yoke for these jeans.

first you slide the two pieces into the attachment. just like on a union special chainstitcher, there is a slight tug on the pant leg in this seam. this will causes puckering like you see on most yoke seams.

then, you sew the pieces together.

there is a traction wheel in the back that keeps things moving.

both sides are done now.

[原料かば]

wow i love this this

whenever i read this i grab all my jeans and compare. its like a class

[mizanation]

now, time to attach the two sides together.

you would think that you would sew them from top to bottom:

but actually, these are always sewn from bottom to top:

the japanese found that all the old levi's were sewn from bottom to top. it is actually much faster to sew them this way. by sewing the bottom part (which is the easier part) first, it provides the stability to sew the top part (which is the harder part) faster. this is another reason why many japanese denim experts think of the 501 as the most perfectly engineered jeans. even the construction of the jeans is engineered for maximum efficiency.

[mizanation]

you have take care when making a lap folded (or felled) seam. if you rush and make a shallow fold like below, you run the risk of making a weak seam.

this is how you should do it. the bottom fabric is deep into the attachment:

the machine is very strong, simultaneously folding and stitching through thick layers of denim.

[mizanation]

when kuniyoshi-san gets to the yoke, he stops and hammers the yoke seam down with a mallet.

time to finish strong:

[mizanation]

now, this is a perfectly sewn center seam. notice that the top of the jeans are perfectly aligned (even though the left side is lower than the right side--i will explain this later). also, notice how the stitches are nice and even--even over the hump where the yoke seams meet. this requires timing and experience on the seamster. a unskilled seamster would have left smaller stitches over the hump because they didn't give the fabric enough push.

kuniyoshi-san checks the line of the seam to make sure it is straight. it is perfect.

[mizanation]

kuniyoshi-san shows me something interesting about this part of the jeans.

notice how the left side is lower than the right side of the seam. he says this unevenness is absolutely necessary or else the jeans won't line up right.

even though the seams are staggered, you can see that the top lines up flush.

he explained to me the physics of why this is, but i actually didn't really understand.

[mizanation]

so, he tore the seam apart and said he would show me the WRONG way to do it!

he resewed the seam without the stagger.

[mizanation]

here is the seam with the right side slightly lower.

you would think that the top would line up perfectly, but no! kuniyoshi-san was right, there is a huge misalignment on top.

also, when you look down the line of the seam, it is crooked. you can see that it pulls to the right. this is not good.

[mizanation]

kuniyoshi-san again ripped the seam apart and sewed the two sides together.

[mizanation]

voila! a perfect center seam. nice and straight and perfectly aligned at the top.

[mizanation]

perfectly straight:

the stagger on the yoke seams insures that the top will be level.

[mizanation]

so, i checked all my jeans to see if they do the stagger on the yoke seam.

turns out most of my jeans don't have the stagger. but most importantly, though, my two pairs of vintage redline levi's DO have the stagger. also, my SC1947's do (which is good since they are supposed to be the most accurate copy of the original 1947 501).

i called up kuniyoshi-san and he says that many companies will cut off the excess at the top. also, he says it's possible that a company might use a custom attachment that somehow corrects this. but he says, if they are using a standard lap fold seamer, than the top will always be uneven if the yoke seams line up.

historically, he says, the stagger also helped make that part easier to sew.

[who8mahrice]

Thanks for the last post, Miz. I've always wondered why on some of my jeans they don't align and thought it was some kind of careless on the part of the company. Now I know better!

[mr.invincible]

how long did it take for kuniyoshi-san to learn how to fully make jeans?

i wonder if I can just go to japan and just work for a year

[selaviso]

to perfect that kind of art takes years if not longer.

[mizanation]

how long did it take for kuniyoshi-san to learn how to fully make jeans?

i wonder if I can just go to japan and just work for a year

just a note: not trying to be rude about your question, just letting you know how kuniyoshi-san learned all this stuff. to learn how to make jeans is not very hard, you can learn the whole process in a couple days. but, to do it well takes many years. please read below!

kuniyoshi-san has been making jeans professionally for over 10 years.

he worked at what many consider the most prestigious jeans factory in the world located in kojima district, okayama, japan.

he has sewn, in part or in whole, over 300,000 pairs of jeans.

now, about getting a job in a japanese jeans factory...

first of all, getting a factory job is probably gonna be very hard. no factory is going to hire a guy with no experience who just wants to work there for a year. they are not going to waste their time training you for the whole year so you can leave before you know anything. also, you work for years at a time at certain stations (pockets, hems, etc...). at the end of your year, you would only know how to make one or two sections of the jeans.

plus, you don't speak japanese or read kanji. communication would be almost impossible. not to mention people in okayama jeans factories have specific "factory speak" which is unintelligible to even japanese folk.

even if you somehow manage to get a factory job, you will be paid very little. even japanese people don't take these jobs anymore. almost all the workers in the factories are now chinese immigrants.

BUT, kuniyoshi-san and i have been thinking of making a denim camp. where you would come stay in okinawa for a week or something and learn the basics of denim from kuniyoshi-san. you would make your own jeans by yourself here. when you are not making jeans, you could chill at the beach or go drinking at the many bars here. this is much better than toiling away in a factory for years.

if anyone is interested in this idea, let me know and i will try to make it happen!

[lenn]

^ would go if my funds allow me to. probably not gonna make it back to japan for the next 2 years though, fuck my student income... should kop a lot less stuff if i wanna go sooner than that.

[thaiison]

this is dope, miz love your documentation, a thread like this works best with lots of photos. keep it up

[LetsGetSerious]

miz,

that sounds like the most killer "how i spent my summer vacation" ever

[snuff_daddy]

i am glued to your updated ...good shit

[ulu]

Awesome awesome idea... I can even do some diving there...

[Busted Seam]

voila! a perfect center seam. nice and straight and perfectly aligned at the top.

Thanks for this fantastic level of detail that makes this one of the best thread on SuFu.

I guess by the maths, he means that in fact there just looks like a stagger - aren't the top levels of stitching level at the edge of the central seam? The right hand merely looks higher, because it's the stitching on the left that continues further. AM I making sense?

Also, could you ask kuniyoshi-san why Levi's jeans seemed to overlap the right-hand half over the left in the 20s and 30s?

[.

[mizanation]

Thanks for this fantastic level of detail that makes this one of the best thread on SuFu.

I guess by the maths, he means that in fact there just looks like a stagger - aren't the top levels of stitching level at the edge of the central seam? The right hand merely looks higher, because it's the stitching on the left that continues further. AM I making sense?

you know what? you do make sense. the seams are not out of line, the just look like that because you can only see the top layer.

i took too pieces of paper and drew lines to simulate the yoke seams. then, i made a little lap felled seam down the middle. if i line up the two seams, the left side always pops out at the top. when i line up the top, then, the left side "seam" is much lower than the right. so, yeah, i just proved that i'm a nerd.

Also, could you ask kuniyoshi-san why Levi's jeans seemed to overlap the right-hand half over the left in the 20s and 30s?

i will ask him when i see him on tuesday.

[Busted Seam]

y

i will ask him when i see him on tuesday.

I just looked in a couple books.

Levi's only cottoned on to the 'staggered' stitching around 1915-1920. All the early jeans lined up the yoke stitching - therefore the vertical lap-felled seam will not align all the way, as you show.

By 1922, they have the stitching that looks staggered - with the right hand side overlapped. And by wartime - I didn't check all my books - the left-hand panel is on top, for the classic 40s and 50s 501 look.

All the old LEes have staggered stitching from the 1920s on, but quite a few of the rival early makes in paul t's book - Stronghold, Special, Boss of the Road - don't.

Thanks and +rep for educating me to a new degree of nerd-dom! Yeah!

[Busted Seam]

Here's DR Heech's cotton duck pants - these are about as early as any Levi's come (or the orignals were, but this is avery good repro). Lev Strauss obviously didn't come to the most efficient stitching for a few years.

It shows qite clearly how the seams seem to line up from the outsidde, but are clearly misaligned on the inside. Together with the single stiched-yoke, this helps give them that cool, really agricultural look.

As requested by some, a few more detailed pics of the Lvc 1873 duck pant:

S

Inside detail

Kuniyoshi-san wlll probably dig the little leather washers inside the pockets - one of the USPs of these jeans is that cotton duck is relatively impermeable to water, so the washers prevent rain seeping in where the fabric is punctured by the rivets.

[mizanation]

cool stuff, busta.