This denim is 12 oz.
I hear that kind of thing, but do you know what oz is?
Actually, I didn't know that (-_-;) I knew it was a unit of weight, but...

So, we decided to check it out!!

What is oz anyway?

An oz is a unit of weight.
"Oz" is an abbreviation for "ounce(s)", which is pronounced ounce.

Many countries around the world use the metric system, so they use units like grams and kilograms for weight.
However, in the United States and the United Kingdom, the imperial system is still used and weights are measured in pounds and ounces.

How many grams in 1 oz?

1 oz is 28.3495g (grams).

Even if this is liquid, it is still measured in fluid ounces. *The plural form is fluid ounces.
This is a standard unit similar to ML (milliliter) and L (liter) in Japan.

However, to make things more complicated, when it comes to liquids the situation is slightly different in the US and the UK.
In the US 1 oz = 29.573 529 5625 milliliters whereas in the UK 1 oz = 28.413 062 5 milliliters so there is a slight difference!
However, it's about 30ml.

The thickness of a T-shirt is expressed in oz (ounces)

I did some research on UnitedAthle, a major T-shirt brand.

The unit of weight of fabric is "ounce (oz)". More precisely, it is the unit of weight of fabric per square yard (oz/yd2). The larger this number is, the heavier and thicker the fabric is. In Japan, grams (g/m2) are more common, but since T-shirts are a product that came from the United States, they are still measured in imperial units.

Hmm... So basically, the commonly referred to 6 oz T-shirt means that it weighs 6 oz per square yard.

So, a 6oz T-shirt is 1 yard = 0.9144M, so it is a T-shirt made using fabric that weighs about 170 grams per 0.9 square meters.

That being said, I'm not really sure what to think ( ゚д゚)

That said, I'm sure I'm not the only one who can't imagine it at all.
I found the approximate ounce weight for a T-shirt!

OZ (ounce) Estimate
3.9 oz or less ⇒ Very thin. It is quite see-through, especially with a white T-shirt.
4.0-4.9 oz. ⇒ A little thin, but recommended for those who prefer softness.
5.0-5.9 oz. -> Standard fabric thickness, not too thin or too thick. Just right.
6.0 to 6.9 ounces: Recommended for those who like a thicker, firmer feel to the fabric.
7.0 ounces or more ⇒ It's very thick and a little hot in the summer, but it feels like you're wearing it comfortably.

These classifications and comments may vary depending on the individual and their values, so please use them only as a guide.

I hope this makes it a lot easier to understand.

About oz of denim

Jeans that weigh around 10 to 14 oz are considered normal weight, while jeans under 10 oz are lighter and sometimes called "light-ounce denim."
Jeans that are over 15 oz are heavy and are sometimes called "heavy ounce jeans."

[voice icon="http://kawanishikaban.com/wp/wp-content/uploads/2017/01/kao_sl.jpg" name="Kawanishikaban" type="l"]It seems that the oz value of denim is determined in the same way as for T-shirts.
It is expressed in oz per yard. [/voice]

summary

After putting everything together, I've realized that the oz (ounce), which I thought represented the thickness of a T-shirt or jeans, is not a measure of thickness, but rather weight.
Well, in the end, weight also relates to thickness, but with advances in technology, we can no longer say that.