Materials & surfaces

What a thing is made of decides what is safe to clean it with. Most useful cleaning rules are properties of the material, not of the object.

• Acrylic

  A polymer, so the things that damage it are solvents and aggressive chemistry rather than acid or alkali. Almost the opposite of the china beside it.

• Aluminium

  Protected by its own oxide layer, but amphoteric: attacked by strong alkalis as well as strong acids, which rules out many oven and dishwasher products.

• Aniline leather

  Dyed the way wood is stained rather than painted. There is no film on top, so anything spilled goes in — and the cleaner darkens it on contact.

• Carpet

  A textile floor covering where the instinctive response to a spill — scrubbing — is the one the trade body specifically rules out.

• Ceramic glass

  The heat-resistant glass used in stove doors and ceramic hobs. Chemically robust and thermally tough, but readily scratched, and scratches are permanent.

• Chrome plating

  A thin decorative chromium layer over another metal. Hard and bright, but once the plating is breached the metal underneath corrodes and no cleaning reverses it.

• Coated aluminium

  Aluminium with an anodic or organic finish on it. The finish is the thing at risk, not the metal — and marks from mistreating it may be permanent.

• Coated spectacle lens

  A coated optical surface where the hazard is not the cleaner but the grit in whatever you wipe it with — and where a scratch is replaced rather than repaired.

• Coated upholstery

  Smooth, non-permeable and still a SOFT surface — which is why the hard-surface spray that seems obviously right for it is the thing most likely to wreck it.

• Concrete and stone paving

  A hard outdoor surface whose weak point is not the slab but the JOINTS between slabs — which is why the standard advice to blast it with a pressure washer is fenced by an angle.

• Copper and brass

  Tarnish is the metal reacting with its surroundings, not dirt on top of it. Every polish that removes it removes metal too.

• Cotton

  A cellulose fibre, tolerant of hot water and alkaline detergents — and measurably degraded by chlorine bleach, which cuts the cellulose chains themselves.

• Engineered quartz

  Ground quartz bound in resin. Non-porous and acid-tolerant where marble is not — but the resin is the weak point, and the products sold for real stone are wrong for it.

• Expanded polystyrene (helmet foam)

  The material inside a cycle helmet, and the one place in this catalogue where a cleaning mistake destroys the function of the object and leaves NOTHING TO SEE.

• Finished leather

  Modern leather carries a water-based finish, which is why the traditional leather products — saddle soap, mink oil, wax — are on the prohibited list rather than the recommended one.

• Finished wood flooring

  The finish is the surface, not the wood — and the two things that ruin it are water and the cleaners people reach for to remove water marks.

• Glass

  Chemically tough and mechanically fragile. Almost all damage to glass is grit dragged across it, not the cleaner used on it.

• Granite

  A silicate stone that resists kitchen acids where marble does not — and on which acidic cleaners are still not recommended, for reasons that are not about the stone.

• Grout

  Cement-based grout is porous and alkaline, and acids dissolve it. That single fact rules out most of what bathroom cleaning advice recommends for it.

• Ivory

  The yellowing everyone wants removed is the material ageing, and the conservation authority's instruction is to leave it. Almost every circulating method attacks a patina rather than a stain.

• Laminate flooring

  A wood-based board under a resin surface. The board is why water is the enemy, and why the trade body rules out steam without qualification.

• Limestone

  Calcium carbonate like marble, but softer and more porous. Everything that damages marble damages it faster, and it absorbs more.

• Memory foam

  An open-cell foam that holds any liquid it takes in and dries from the inside outwards. The manufacturer's instruction is not a cleaning method — it is that it should never get wet.

• Mirrored glass

  Glass with a reflective backing and exposed edges. The trade body's guidance rules out both vinegar and ammonia — which is nearly everything sold for cleaning it.

• Non-stick coating

  A behaviour, not a material — and the sources that give cleaning rules for it usually decline to say which coating it is. So does this record.

• Nubuck

  Aniline leather sanded to a short nap — and the trade's cleaning method is to sand it again, because the soil is in the fibres rather than on them.

• Painted walls

  A soft coating that is still curing for weeks after it looks dry, and that is damaged by water as readily as by any cleaner.

• Plated and coated tap finishes

  Modern taps are a coating on a metal, microns thick. The finish decides the rules, and the rules genuinely differ between finishes on the same basin.

• Polished marble

  A calcium carbonate stone with a polished finish. Chemically attacked by acids, including household ones, and the damage is permanent.

• Polyester

  A synthetic fibre that resists the chemistry which degrades cotton and wool, and is instead limited by heat — and it holds oily soil more stubbornly than either.

• Porcelain tile

  The trade defines porcelain by a number: water absorption of 0.5% or less. That number is why one tile stains and another does not.

• Seasoned cast iron

  Bare iron protected by a baked-on oil layer. Water is the enemy, not detergent — and the manufacturer says so more plainly than the folklore does.

• Silver plate

  A microns-thin layer of silver over a base metal. Everything that cleans sterling also thins the plating, and once it is through there is nothing underneath to polish.

• Solution-dyed acrylic

  Outdoor fabric with the colour built into the fibre rather than applied to it — which is why its maker specifies bleach where the rest of the catalogue prohibits it.

• Stainless steel

  Steel protected by a self-repairing chromium oxide layer. Resistant to most household cleaning, and specifically vulnerable to chlorides and to abrasion across the grain.

• Sterling silver

  92.5% silver, and the only material here where the standard domestic treatment permanently removes some of the object. Tarnish contains silver, so cleaning it off costs silver.

• Suede

  Not finished leather with a texture — a different cut of the hide, porous and undyed at the surface, where even clean water leaves a ring if it is hard.

• Upholstery fabric

  Carpet advice does not transfer to it. The manufacturer's rules start with what NOT to vacuum with, and water is on the prohibited list rather than the method list.

• uPVC

  The commonest window frame in the UK and the material with the most confident wrong advice attached to it. The manufacturer permits a cream cleaner — sparingly, and not on woodgrain.

• Vinyl flooring

  A polymer floor whose wear surface is often a finish rather than the vinyl itself — which is what solvents and all-purpose cleaners attack.

• Viscose and rayon

  A cellulose fibre that the professional body describes as very sensitive to water — and the shape can be lost to a dissolving finish rather than to the fibre.

• Vitreous china

  The one bathroom surface where the manufacturer permits a soft abrasive. The fittings around it are what you have to protect.

• Vitreous enamel

  Glass fused onto metal. Hard, but a scratch goes through to the iron and does not come back.

• Waterproof outerwear

  The one garment family where the manufacturer prescribes the tumble dryer rather than warning about it — because heat is what restores the water repellency.

• Wool

  A protein fibre. The wool industry body advises against bleach of any kind and against enzyme detergents, and heat with agitation felts it irreversibly.