At first skeined pile, which is almost yellow, has to be bleached. In this region, first of all, pile is washed by water and soap.

Then it is preserved in 2% to 5% of sodium hydrosulfite and 1% to 3% formic acid (85) bath, for half an hour in boiling condition.

To bleach it completely, temperature has to be 70 to 80 degree C. After bleaching it is washed very well in hot water, otherwise the remaining hydrosulfite may destroy the next dyeing.