Some of Levi’s vintage jeans are called “66 models”.
I don’t know if the “66 model” is called only in Japan or in the world.
The “66 model” is not the 1966 Levi’s 501.
Jeans from the late 1960s to the 1980s.
The etymology of “66 model” is that there is a flasher with a back pocket when it is new.
At the bottom, there is a description of the year when the registration of Copy Right was renewed in 1966.
There is a theory that the number on the back of the top button is 6, but the number on the back of the pocket is probably the factory number, and I think it is correct from the flasher’s year notation.
There are three types of “66 models”, which are “Big-E, Small-e” and are divided into “early half” and “latter half”.
“66 model-early half” that was manufactured in “1969s to mid-1970s”
Among them, it changed from “bigE” to “small e” from around 1969, and all changed to “small e” around 1971.
In other words, at this time, “big E” and “small e” are mixed even if the denim and details are the same.
There are two types.
“66 model” but “bigE”
This is more popular and will be overpriced.
The difference between the 501XX bigE before 1969 and the “66 model” bigE is whether or not there is a black stamp with the letters “CARE INSTRUTIONS INSIDE GARMENT” on the paper label.
In addition, the right foot of the letter “R” on the front button is longer to the left, and the pocket bag also has the stamp letter “CARE INSTRUTIONS INSIDE GARMENT”.
In “66 model-latter half”, “CARE INSTRUTIONS INSIDE GARMENT” is written on the inner display tag instead of the pocket bag.
The “66 model-latter half” is from 1977 to 1980.
After that, the 501 will use Selvedge until 1983.
After that, the model using selvedge denim will disappear until the reprint comes out in 501.
501 “Selvedge denim” from 1980 to 1983 is called “Red line model” in Japan.
What is the difference between “66 model-latter half” and “red line model”?
It is divided by the shrinkage resistance written on the inner display tag.
8% = “66 model-latter half”
10% = “Red Line Model”
As I explained so far, some people say that “66 model-early half” started around 1973.
I think that “big E” is mixed and it is counted in XX before that.
There is no 100% accurate answer.
Levi’s can’t be making jeans while thinking that it will be categorized by details in various places later.