Laundry bluing is a product used to wash white fabric items that have become slightly off-white over time. The blue dye in the product gives fabric the appearance of regaining a pure white color. Bluing is somewhat less common in areas where products that keep white clothing very white exist, but it is still used by some people to refresh white clothing. There are some alternative uses for laundry bluing as well, including dying hair and possibly even relieving itching due to bug bites.
Usually, laundry bluing is sold in a liquid form for ease of use, but it also exists as a solid. The solution is typically diluted in cold water and added to a washing machine before either the wash or rinse cycle. It is important to follow the directions on the laundry bluing package, as different products are used in different amounts. When using bluing, it is absolutely essential to make sure that it is mixed thoroughly, as undiluted bluing can cause blue spots to appear on clothing. For this reason, bluing is usually mixed thoroughly in a bucket and then applied to clothing, which minimizes the risk of discoloration.
Essentially, laundry bluing is very diluted blue dye. This means that using too much bluing can actually dye clothing a blue tint even when the solution is thoroughly mixed. Sometimes, this effect is used intentionally in order to restore the original appearance of blue jeans. While bluing works best on white clothing, it can also be used to brighten colors.
The reason that laundry bluing causes white textiles to appear whiter is because it effectively cancels out any yellow or gray tint the textiles may have picked up. It does not actually remove any color or stain, but it does give the appearance of a whiter fabric. One of the main reasons people use bluing instead of bleach is because bleach is much harsher than bluing and can damage textiles. Bluing cannot, however, remove stains using the same mechanism as bleach.
There are some alternative uses for bluing as well. For example, some people use bluing to make swimming pools look more blue, and others use the dye on hair to make hair look whiter. These problems can often be solved using other chemicals more suited to the task, but if someone has laundry bluing around the house, it can be possible to make this product work. In some areas, bluing is used as a folk cure for mosquito bites, although the effectiveness of this application has not been thoroughly researched.
