Types of Stains

Examples: Red wine, coffee, tea, beer, juice, berries

Tannins are polyphenolic plant compounds that hydrogen-bond to protein fibres (wool, silk) and form coloured complexes on cellulose fibres (cotton, linen). They oxidise on contact with air — a tannin spill that looks pink becomes a persistent burgundy stain as it dries.

The chemistry: The pigmented quinone forms of tannin can be reduced or chelated. Oxygen-based bleach (sodium percarbonate) converts the quinone back to a colourless leuco form. Enzymatic treatments are less effective here than simple oxidation.

Examples: Blood, sweat, urine, egg, milk, vomit

Protein stains contain amino acid chains from biological sources. In their natural state they are water-soluble enough to rinse out. The danger is heat: above approximately 40°C, the protein denatures and cross-links with the fibre, becoming permanently embedded.

The chemistry: Proteolytic enzymes (proteases) break the peptide bonds in the protein chain, converting it to small water-soluble fragments. This is why enzyme detergents are the gold standard for protein stains — and why the same enzymes must never be used on wool or silk (also protein fibres).

Examples: Cooking oil, butter, grease, mayonnaise, salad dressing

Lipid stains are hydrophobic — they actively repel water. Rinsing with water alone does nothing and can spread the oil across a larger area. The stain must first be emulsified with a surfactant before any rinsing has effect.

The chemistry: Surfactants (found in dish soap and many detergents) have a hydrophilic head and a hydrophobic tail. The tail embeds into the oil droplet while the head faces outward into water — forming a micelle that holds the oil in suspension and allows it to be rinsed away.

Examples: Ballpoint pen, permanent marker, printer ink, highlighter

Ink stains contain dye pigments suspended in a polymer binder. The binder is what makes ink adhere to paper — and to fabric. As the binder cures or dries, the dye becomes progressively more locked into the fibre structure.

The chemistry: Isopropyl alcohol is the most reliable first-step solvent because it dissolves most polymer binders without severely damaging fabric. Permanent marker uses a resin binder that responds to acetone or alcohol. Water-based highlighters respond to plain water before drying.

Examples: Grass, mud, dirt

Organic outdoor stains combine multiple components: plant pigments (chlorophyll in grass), tannins from soil, and mineral particles. Mud in particular benefits from a completely different approach — letting it dry before treating is correct here, unlike all other stain types.

The chemistry: Chlorophyll in grass contains a magnesium porphyrin ring — a stable pigment that bonds strongly to cellulose fibres. Enzyme detergents outperform plain detergent on these stains because they break down the organic matrix holding the pigment to the fibre.

Examples: Ketchup, tomato sauce, mustard, chocolate, berries

Food stains are composite stains — they contain a protein component, an acidic or pigmented component, and often a fat component. Treatment must address all parts. The protein component sets with heat; the pigment component may require oxidation.

The chemistry: Mustard contains turmeric, whose curcumin molecules form a particularly stable bond with cellulose that requires strong oxidising agents to break. Tomato's lycopene is a carotenoid pigment that responds to both surfactants and mild bleaching agents.

Examples: Lipstick, foundation, mascara, general makeup

Cosmetics consist of pigments dispersed in an oil, wax, or silicone base. The base material determines the primary removal approach. Oil-based cosmetics need a surfactant; wax-based products need a solvent.

The chemistry: Pigment particles in cosmetics are very small and can penetrate fabric deeply if rubbed. The carrier material (oil, wax, silicone) determines the primary removal strategy: dish soap for oils, white spirit for wax, micellar water for silicone-based products.

Examples: Candle wax, crayons

Wax stains are unique because the correct first step is to harden the wax completely before attempting removal. Liquid or semi-liquid wax treated immediately spreads into the fabric weave and becomes much harder to extract.

The chemistry: Solid wax is brittle and can be broken away from the fabric surface. The remaining wax embedded in fibres can be melted and drawn out by capillary action into absorbent paper using a warm iron. The wax migrates from fibre to paper rather than spreading further.

Examples: Superglue, PVA glue, tape residue

Adhesives contain polymer resins that form mechanical bonds with fabric fibres as they cure. The removal approach depends entirely on whether the adhesive has cured. Fresh adhesive often rinses out; cured adhesive requires a solvent.

The chemistry: Cyanoacrylate (superglue) cures through anionic polymerisation triggered by moisture. Acetone reverses this by dissolving the polymer chain. PVA glue is water-based and soluble before curing but becomes insoluble once dry. Always test solvents on an inconspicuous area.

Examples: Water-based (acrylic) paint, oil-based paint

Paint treatment is entirely determined by the paint type. Water-based acrylic paint treated while wet is easily removed with water and soap. Once cured, acrylic paint forms a plastic film on fabric fibres that is essentially irreversible. Oil-based paint requires white spirit at any stage.

The chemistry: Water-based acrylic paint uses a polymer emulsion that dries by water evaporation and oxidation. Once the polymer network forms, water no longer penetrates. Oil-based paint polymerises through oxidative crosslinking, requiring an organic solvent to dissolve the cured resin.

Examples: Metal rust, iron deposits from water

Rust stains are iron oxide particles that have formed a coordination complex with the fabric fibre. They cannot be removed with standard detergents because the iron oxide is not soluble in water.

The chemistry: Oxalic acid (found in lemon juice) chelates the iron(III) ions, forming a water-soluble iron-oxalate complex. This converts the insoluble rust compound into something that can be rinsed away. Chlorine bleach reacts with iron oxide to form even more intensely coloured iron chloride compounds — never use bleach on rust.