What is Mercerized Cotton?

I bought this yarn from Elann and I didn't know what Mercerized cotton was. I understand now and thought I would share the information.

Mercerized cotton

From Wikipedia, the free encyclopedia

Mercerization is a treatment for cotton fabric and thread mostly employed to give cotton a lustrous appearance. The series of processes was devised by John Mercer of Great Harword, Lancashire, in the middle of the 19th century, but didn't become popular until improvements were made to the process in 1890.

Mercerized cotton, also known as pearl or pearle cotton, is cotton thread (or cotton-covered thread with a polyester core) that has been treated with sodium hydroxide (NaOH). The thread is given a caustic soda bath that is then neutralized with an acid bath. This treatment increases luster, strength, affinity to dye, resistance to mildew, and also reduces lint. Cotton with long staple fiber lengths responds best to mercerization.