Stain Removal and Spotting Techniques
This domain tests whether you can identify a stain, choose the right chemistry and remove it without damaging fibre or colour.
Core rules
- Identify the stain, the fibre and the dye fastness before touching it. Test every agent on an inside seam or hem.
- Work from the back of the stain over a towel, blot rather than rub, and use a clean area of cloth each time.
- Protein stains such as blood, egg, milk and grass need cold water and protease enzyme. Hot water coagulates them.
- Oil and grease need solvent or absorbent powder, not water alone.
- Tannin stains from tea, coffee and wine respond to acid, such as dilute vinegar or a tannin remover.
- Rust needs oxalic acid or a proprietary rust remover. Chlorine bleach makes rust worse.
- Starch stains need amylase; fat needs lipase. Oxygen bleach is safer for coloured cotton than chlorine bleach.
Worked example
A dried blood stain is on a white cotton shirt. Reasoning: blood is protein, so hot water would set it. Soak in cold water, apply enzyme detergent, wait, then rinse. If a mark remains, use oxygen bleach at 40-60 C. Chlorine bleach is acceptable only on white cotton and only after checking that no coloured trim is present.
Traps that cost marks
- Rubbing a stain and spreading it.
- Using hot water on protein stains.
- Using chlorine bleach as a universal remover on wool, silk, acetate or coloured fabric.
- Skipping the colourfastness test on an inconspicuous area.