How the formation of growth marks and wrinkled grain minimised?
Growth marks and wrinkled grain are formed due to differences in texture in single section of the skin. Uneven curing, overloaded liming drums or insufficient liquor, high concentration of liming chemicals, intensive swelling at low temperatures are the major reasons. Also due to insufficient removal of adhering dung, long hair, residue of flesh and fat in some sections. Inadequate penetration of tanning also causes the formation of wrinkled grain. The formation of growth marks and wrinkled grain can be minimised by even curing throughout, green fleshing, mild liming process by addition of liming chemicals in gradual portions, replacement of sodium sulphide by sulphydrates. Drum/paddle liming preceded by paint liming also reduces the formation of these marks.
