The kit · absorbent
Cornstarch: what it removes and where never to use it
Fine starch powder can absorb some fresh oil. Talc and baby powders have different formulations and are not interchangeable products. Avoid inhaling powders.
- pH
- 6–7
- Safe on
- 0 materials
- Never on
- 0 materials
- UK name
- cornflour
01 How to use it
Cover the fresh oily stain completely, leave 15–30 minutes (overnight for leather and suede), brush or vacuum off, repeat while the powder still darkens.
How it works
Absorbents pull fresh liquid and oil out of a material by capillary action, like a wick. They are the gentlest first step on things you cannot wash.
The table gives general restrictions; an unlisted restriction is not proof that a product is compatible.
02 What it works on
- Oil and fat
Cornstarch is strongest against oil and fat. It is part of the method in 135 stain files, for stains such as grease, butter, chocolate, gravy, salad dressing and ice cream.
03 Where it is safe
| Material | Verdict | Why |
|---|---|---|
| Clothes | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| White shirt | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Jeans | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Linen | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Sheets and bedding | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Towels | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Baby clothes | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Polyester | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Leggings and activewear | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Wool and cashmere | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Silk | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Rayon and viscose | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Carpet | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Wool rug | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Fabric couch | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Microfiber couch | Test first | Brush out every trace; white powder can lodge in dark pile. |
| Velvet upholstery | Test first | Brush out every trace; white powder can lodge in dark pile. |
| Car seats | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Mattress | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Leather | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Suede and nubuck | Test first | Brush out every trace; white powder can lodge in dark pile. |
| White sneakers | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Marble | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Granite | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Quartz countertop | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Wood furniture and floors | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Tile grout | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Painted walls | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
| Plastic containers | Test first | No material-specific permission is established by this general entry. Check the exact item and product labels and pretest; if compatibility is unknown, consult the manufacturer or a professional. |
04 How the files use it
Cornstarch appears in 135 stain files. The steps it is used in most:
- Draw out the oil (123 files): Fine powder pulls fresh oil out of the clothes by capillary action, like a wick. It is the gentlest way to remove the bulk of the oil.
- Repeat the powder, then brush (16 files): On suede, every liquid risks a ring; powder and friction are the safe tools.
05 Files that use it
- Grease and cooking oil on clothes
- Butter on clothes
- Chocolate on suede
- Gravy on suede
- Salad dressing on clothes
- Ice cream on suede
- Peanut butter on clothes
- Foundation and concealer on suede
- Lipstick on suede
- Nail polish on suede
- Sunscreen on clothes
- Bronzer, blush and eyeshadow on suede
- Perfume on suede
- Hair and body oil on clothes
- Drool and yellow pillow stains on suede
- Ballpoint ink on suede
- Mud and dirt on suede
- Tree sap on suede
- Bike chain and motor grease on clothes
06 Myth files
- Does baby powder or cornstarch remove grease stains? On fresh oil, yes: fine powders wick oil out of fibres. They are the first step, not the whole fix.
07 Questions
What stains does cornstarch remove?
It works best on oil and fat, which is why it appears in the files for grease, butter, chocolate, gravy and salad dressing.
How do you use cornstarch safely?
Cover the fresh oily stain completely, leave 15–30 minutes (overnight for leather and suede), brush or vacuum off, repeat while the powder still darkens. Test on a hidden spot first.
What should you never mix with cornstarch?
This reference cannot establish that any commercial cleaner has no dangerous mixing partner. Do not combine cleaners unless their exact manufacturers explicitly permit the use; rinsing alone does not establish compatibility for later treatment.
Where should you never use cornstarch?
Nowhere on file is ruled out completely, but check the material file before using it on anything delicate.