Similarly to gold, the quality of which is measured in karats, the general quality of silk fabric is measured in a specific unit. Some wrongly call it silk karats, but the correct term is called momme or monme [mOn-m-eh] from the Japanese 匁.
What is it?
Momme is not some arbitrary measurement, it is simply a unit measuring the density of silk per a specific area. Not for weight, but for density! Usually, if a piece of silk is dense (it has a higher weight per square foot or per square meter) it is of higher quality. However! If it is too dense silk starts losing its qualities and becomes stiffer.
The denser silk is stronger, but a too dense silk is not as soft. The silk pillowcases from satin, which B. Version offers are of 22 mm mulberry silk, which is the optimum between density, quality and softness.
One of B. Version’s designer 22 mm silk pillowcases that combine luxury, tradition and modern conceptions.
Many shops offer scarfs, shawls, neckties and silk pillowcases, but never say what is the density of the silk product that they are offering. They are just speculating with the fact that you do not know the density of the silk.
If you are curious: How is it calculated?
Most likely this unit of measurement originated in the Japanese trade of silk with the English speaking world, but today it is used in the international silk trade. It is calculated in the following manner:
The weight of 100 yards of 45 inch silk fabric measured in pounds.
If such a piece weighs 16 pounds, the silk is 16 mm (momme), if it weighs 20 pounds the silk is 20 mm and so on.
Not to be confused with the unit for weight with the same name
Traditionally Japanese use a unit for weight with the same name. It is calculated in a different manner and it equals about 3,75612 grams. This was the weight of the smallest Japanese iron coin mon. The difference is that this unit measures the weight, while the silk monme or momme measures the density of silk (how much it weights per unit of area).