Just as Italy is renowned for its high quality Cashmere so is Egypt renowned for its high quality cotton.
The finest cotton tends to be grown in the fertile Nile Delta (Egypt) and then selected based on grade from the bales produced. “45 Cotton” is one of the highest grades available. And Giza is one of the premier growing regions.
So “Giza 45” Cotton refers to 45mm long fibres selected from the Giza area.
Consistent quality is ensured by a quality assurance program run by the Alexandria Cotton Exporters Association.
A similar criteria is found with cashmere and other high quality natural fibres. Generally the longer the length the better feel the resultant fibre has. Typically a ‘normal’ cotton fibre is a few mm shorter at 38mm.
Other factors affect the quality the shine and the feel. For example smoother microscopic scales on the fibre will reflect more light and make the fibre shinier. In the case of Giza 45 cotton the average diameter of the fibres is also thinner than most. This enables a greater TPI (threads per inch) and to a lesser degree a more flexible end fabric.
Further factors are the micronaire. This looks at the chemical structure of the fibre. Thus the distribution of cellulose molecules within the fibre affects wear and softness over time.
More information about the cotton market can be found on one of the main cotton supplier’s websites (look for Emilcotoni and “The Cotton Report”)
Hopefully this infomration has been of use for anyone sourcing high quality cotton.