It also includes the finishing of these materials by the use of blueing, starch, and heated irons, to restore as far as possible their original appearance.
"Ontario Teachers' Manuals: Household Management"
Ministry of Education
6. blueing: Open out each piece and place one or two at a time in a tub of blueing water for just a moment; wring tightly, and shake out each piece.
"Ontario Teachers' Manuals: Household Management"
Ministry of Education
The blueing tends to counteract any yellow tinge in the clothes, making them appear whiter.
"Ontario Teachers' Manuals: Household Management"
Ministry of Education