Have you ever received complaints about white garments turning gray?
One of two problems usually causes this discoloration.
Most whites are treated with fluorescent whiteners or optical brighteners during manufacturing to achieve a desired shade of white. Brighteners decompose with age, exposure to light, or, in some cases, the heat of cleaning. Washing the item in bleach will also destroy the brighteners. Decomposition causes the white fabric to appear dull and dingy, or have a slightly yellow or green color.
If the garment has a gray cast, the discoloration is usually due to redeposition of soils, dyes, carbon particles, or other impurities that were in the solvent during the cleaning process. Improper filtration or distillation of the solvent is frequently the cause of this type of discoloration.
Graying of fabric can also occur in laundering. Overloading the washer or using low water or detergent levels contributes to this problem since soils are not flushed out in rinsing but redeposit on the items in the load.
Redeposition in drycleaning is very difficult to remove. In some cases, re-cleaning in clear solvent may improve the appearance. It may be possible to remove impurities from laundered items by rewashing in a load with adequate water and detergent levels.
The change in whiteness caused by decomposition of fluorescent brighteners is permanent and may be considered a manufacturer defect if the item is relatively new and has been cleaned according to recommended care instructions.
Slight variations in color between components of a white garment may not be noticed if all pieces are cleaned in the same batch.
For more information, see the following bulletins in DLI's Drycleaning Encyclopedia:
- Shirt Laundry Procedures No. 132 "How White are Your Shirts"
- Technical Operating Information (TOI) No. 667 "Greying of Fabrics in Drycleaning"
- TOI No. 744 "Importance of Adequate Solvent Levels in the Drycleaning Machine"
Photo Caption: Redeposition caused graying in this sweater.