Microfiber cloths

Choosing a car microfibre towel by GSM and edge

Which microfibre towel does your car need? It comes down to the fabric weight in GSM and to the edge. Light towels around 250 GSM wipe off polish and sealant residue, heavy ones from 900 GSM handle drying, and a cut Edgeless edge keeps the paint scratch-free while you work.

A car microfibre towel is a fabric woven from split polyester and polyamide fibres that come out thinner than a human hair. Splitting them creates wedge-shaped fibre ends that grab dirt and lock it into the weave instead of dragging it across the paint. The fabric weight in grams per square metre, GSM for short, decides whether a towel wipes off, polishes, or carries water.

• GSM is the number you sort a towel by. Grams per square metre tell you how much fibre mass sits on the surface. Between 200 and 300 GSM you get the short pile for wiping off, between 300 and 600 the all-rounder, and from 600 up the drying towel starts. What that means for you: a single number on the label already tells you what the towel was built for.
• The edge scratches the paint, not the face. An overlocked edge is made of polyester yarn that is harder than the fibre next to it and runs across the clear coat as a thin ridge as you wipe. Edgeless towels are ultrasonically cut and do not have that ridge. On painted surfaces that is the difference that matters more.
• Bad washing kills more towels than bad technique. Fabric softener coats the capillaries as a film and robs the towel of its pull, and cotton lint from a shared drum clogs the pile. Washed at 60 degrees, without softener and separately from cotton, a good towel lasts well over a hundred rounds.

Day-to-day from Detailing1: We regularly get questions about towels that, after a few months, only push water around instead of soaking it up. In almost every case fabric softener was involved, often indirectly through residue in the drum or through dryer sheets. Softener is made to do exactly one thing, wrap itself around fibres, and a wrapped microfibre has no open capillaries left. Wash your towels with a liquid detergent, no softener and no bleach, and leave the softener compartment empty. A towel that has already gone slick you can often bring back with two or three hot cycles run with no detergent at all.

What the GSM weight tells you about a towel

GSM stands for grams per square metre and describes how much fibre mass sits on the face of a towel. More mass means a higher pile and more it can soak up.

Picture two towels the same size side by side, one at 250 grams per square metre, the other at 950. The heavy one carries a dense, tall pile and behaves like a terry bath towel; the light one more like a fine tea towel. Day-to-day that means the heavy one carries water, the light one works the surface with precision.

What GSM does not tell you is quality. A coarsely woven towel at 500 GSM can run harder over the clear coat than a finely knitted one at 300. Fabric weight describes the amount of fibre, not how fine it is, not the weave, and not how the edge is finished.

The second number usually sits right next to it, the blend ratio. Eighty parts polyester carry structure and cleaning bite, twenty parts polyamide bring softness and absorbency. A seventy-thirty blend feels noticeably softer and takes up more, though it costs more to make.

What really matters in the end is whether the fibre has been split. Unsplit microfibre pushes dirt along in front of it, split fibre opens into wedge-shaped ends and locks particles into its capillaries. The test for it costs nothing: a split towel snags lightly on dry skin, an unsplit one just glides over it.

From our day-to-day at Detailing1: most bad buys happen because people look at the gram figure and nothing else. Grab a heavy drying towel for polish residue and you are fighting a pile that swallows the residue instead of lifting it off, then you are left scratching your head over streaks in raking light.

Light, medium and heavy, three classes with three jobs

Three weight classes cover the whole job on a car. Light up to about 300 GSM, medium between 300 and 600, heavy from 600 up.

The light class between 200 and 300 GSM has a short pile and little bulk of its own. It pulls off sealant residue, polish haze and quick-detailer film without soaking up much product itself. The Koch-Chemie Pro Glass Towel 230GSM microfibre glass towel works the glass streak-free because it barely sheds any lint.

In the same class sits one of the best-selling working towels in our range, the THE COLLECTION „Allround / Coating 245" short-pile Edgeless microfibre towel (245 GSM). It is kept deliberately thin so a freshly laid ceramic layer gets levelled evenly and no High Spots are left standing.

The medium class between 300 and 600 GSM is the all-rounder for the interior, plastics, taking off polish and the round with the quick detailer. The Koch-Chemie Pro Allrounder Towel „315GSM" microfibre polishing towel and the THE COLLECTION „Allround / Coating 300" short-pile Edgeless microfibre towel (300 GSM) cover this range.

As the pile gets longer, the reserve for product residue grows. The Koch-Chemie Polish and Sealing Towel 520GSM microfibre towel and the SONAX PROFILINE MicrofaserTuch „Soft Touch" microfibre towel take up spent polish without dragging it across the surface.

From 600 GSM up the drying class begins. Microfibre holds roughly seven times its own weight in water, so a Koch-Chemie Pro Drying Towel 950GSM microfibre drying towel carries a whole half of the car before you have to wring it out. The THE COLLECTION „Aqua" Twisted Loop drying towel (1500 GSM) goes a step further with its twisted fibre loops.

The edge decides whether the paint gets scratched

It is not a towel's face that draws fine scratches into the clear coat, it is the rim. And on a lot of cheap towels that is exactly where the hardest material sits.

An overlocked edge is wrapped in polyester yarn. That yarn is a smooth, hard thread, clearly firmer than the soft microfibre beside it, and as you wipe it runs across the surface as a thin ridge. You can spot it: the classic fine arcs in raking light often end exactly one towel-width across.

Edgeless towels do not have that ridge. They are cut with ultrasound or laser, and the cut edge is welded shut in the same moment. What is left is an edge of the same soft material as the face, it does not fray and carries no foreign yarn. For painted surfaces that is the safe build.

Between the two worlds sits the bound satin edge, often called Silk Banded. A soft, smooth band closes off the rim, which keeps the towel's shape better than a plain cut edge. On glass and interior it is a good call, on freshly polished black paint Edgeless stays the finer choice.

Sewn-in labels fall into the same risk bucket. A stiff label in the corner is, if anything, harder than any seam and sits right under your hand as you wipe. We always trim labels flush before a towel ever touches paint for the first time.

Stitched edges still have their place, namely where toughness counts. Door sills, wheel arches, the engine-bay area, tools and wheels take the sturdier seam just fine, and towels like that survive rough work longer. The rule is simple: stitched edge for everything except paint and glass.

One towel per job instead of one for everything

A microfibre towel is a store. Whatever it has picked up stays in there until wash day, and that is exactly why you split up the jobs.

The easiest way is by colour. We recommend a fixed colour code, because it works in the flow without you having to think: one colour for paint and sealant, one for glass, one for the interior, one for wheels and sills. Which colour goes where is up to you, sticking to it is the whole point.

Glass earns its own colour, because there every bit of product residue shows up straight away. A towel that has seen plastic dressing before will smear the glass in a way no glass cleaner can fix afterwards. Short-pile, light material and a towel that has never seen anything else settle the matter for good.

For the round with the quick detailer the same holds in a milder form. Here you are working dry paint with a minimal slip film, so the softest, cleanest towel in the stack belongs on the job. Two towels at once is the standard, one takes up, one buffs after.

And the limits: a microfibre towel is no substitute for chemistry. Baked-on bugs, tar and rail dust do not come off with more pressure, they come off with the right product and dwell time. Wipe dry over dirty paint and you are using the towel as sandpaper, and a towel that has hit the floor never goes back on the paint.

Splitting up the jobs goes beyond the towel itself. Washing calls for a wash mitt with a long pile that pulls dirt down and away from the paint, drying calls for a big drying towel. The full run-down of every build is over on Towels.

Sixty degrees, no softener, washed apart from cotton

Microfibre is plastic, and plastic forgives heat and additives less well than cotton does. Three rules keep the stack in shape for years.

Sixty degrees is the right compromise. Any colder and the grease from polish and dressing products will not reliably lift out of the pile, much hotter and polyester gets close to its softening range and the fine fibre ends fuse into a smooth face. A glazed towel takes up nothing anymore and cannot be saved either.

Fabric softener stays out completely. It is built to wrap every fibre in a slip film, and that film is exactly what seals the capillaries microfibre uses to take up water and dirt. In practice: the towel feels fluffy and then just pushes the water around. The same goes for dryer sheets in the tumble dryer.

Washing apart from cotton is the rule that gets skipped most often. Cotton sheds fibres in every cycle, and they lodge in the microfibre's pile. You only see the result on the glass, when an otherwise clean towel suddenly leaves lint behind. Bath towels, rags and jeans belong in a different drum for that reason.

For detergent, a plain liquid one with no bleach and no optical brighteners does the job. Powder does not always dissolve fully on short cycles and settles into the weave as residue. An extra rinse pays off, because it carries exactly those leftovers out.

Dry on low heat or on the line. Sort the towels by job as you collect them, and then wheel and paint towels never end up in the same drum together. Looked after properly, a good towel's life runs well past a hundred washes, and that is the real reason paying up for better quality adds up.

Which towels belong in your basic kit

For the full car-care routine you do not need a big spread of builds, you need three types in enough numbers.

The starting point is one drying towel, a stack of all-rounders and two glass towels. For the drying towel you grab the Koch-Chemie Pro Drying Towel 950GSM microfibre drying towel or the THE COLLECTION „Aqua" Twisted Loop drying towel (1500 GSM), plus the Koch-Chemie Pro Glass Towel 230GSM microfibre glass towel for the windows.

As the workhorse of the stack, the THE COLLECTION „Allround / Coating 300" short-pile Edgeless microfibre towel (300 GSM) has won us over. If you want a bit more pile for polish and wax residue, reach for the THE COLLECTION „Allround 365" short-pile Edgeless microfibre towel (365 GSM).

If your car wears a ceramic coating, one more towel joins the kit, one used only for levelling. The Koch-Chemie Coating Towel 300GSM microfibre towel for ceramic coatings and the THE COLLECTION „Allround / Coating 245" short-pile Edgeless microfibre towel (245 GSM) are short enough in the pile so nothing stays behind.

If you regularly do several cars, the maths changes. Then numbers beat specialisation, because a fresh towel per panel is quicker than any rescue job on a clogged one. For the wash itself the Koch-Chemie Exterior Wash Mitt 640GSM microfibre wash mitt rounds out the kit, for the drying round the SONAX PROFILINE MicrofaserTrockenTuch „PLUS" microfibre towel.

An honest take to finish. On painted surfaces the gap between a solid towel and a top-end one is smaller than the price range suggests. The biggest jump you make is switching from a stitched to a cut edge and splitting your towels by job without fail. Everything after that is fine-tuning, and you can dial that in at your own pace.