To separate the flax fiber from the plant stem of flax is called Retting. Retting is four types. They are:
  1. Dam retting.
  2. Water retting.
  3. Dew retting.
  4. Chemical retting.
Dam retting: The flax bundles are immersed into dams or ponds for about 10 days. This method is no longer practiced except Egypt.
Water retting: In water retting the flax is tied in bundles are covered with water in a tank, Fermentation caused by bacteria. When the fermentation has reached the appropriate stage the fibers can be separated quite easily. To avoid the over retting, must be observed carefully at intervals. This operation takes about 3 weeks.
Dew retting: In this process flax bundle are spread out grass and allowed to ferment. It is commonly used in regions where water is in short supply. i.e. U.S., S.R. and Europe. The advantage of dew retting is better color is obtained and less expensive.
Chemical retting: In this process retting is done by boiling the flax with alkali or oxalic acid at atmospheric. The advantage of chemical retting is quicker process. And the disadvantage is costly process, high risky process.