Skip to content
A climber's open hands covered in chalk in the sun at a climbing crag in the uk




The famous John Gill began experimenting with chalk as early as 1954. As a freshman at Georgia Tech, he saw things a little differently, bouldering for the sake of bouldering rather than just using it as a training exercise to improve strength and endurance for climbing which, at the time, was seen as more of an extension of hiking and exploration than its own stand-alone discipline. As a gymnast, Gill would often use chalk to aid his grip while climbing rope, his specialist event. Thinking outside the box he made the connection “Well, if you chalk up for this, you might as well chalk up for a climb too”. Gill was the first climber to use chalk to benefit his grip while climbing rock, and his chalky hand marks became his calling card. 

Despite the benefits Gill found, resistance from the climbing world throughout the 1970s and 80s was strong, with movements like ‘Clean Hand Gang’ protesting at what they saw was the destruction of the rock aesthetic with chalk marks, and the watering down of climbing from an adventurous pursuit to just a mere sport. Although controversial for decades after Gill’s experiment, using chalk slowly gained traction amongst climbers who experienced the benefits. Over the year advances in rope technology and fall protection made risky dynamic moves became safer and more commonplace in free-climbing, compounding the benefits of chalk for extra grip. Eventually, even strong opponents of chalk such as Pat Littlejohn were coming around, putting up his first route using chalk, White Hotel in 1984.


A length of wood with Rosin, POF or colophonium dripping from its top surface.


POF or Rosin is a kind of synthetic pine resin that has been in use since the 1930s and is still in use today, mainly in France. Usually carried in a rag or cloth, the Bleausards (Fontainebleau locals) would use the sticky white resin on their hands, shoes and even the rock to give better friction whilst climbing. As an alternative way to improve your grip, POF may sound like a bit of a home run. But hold your horses. It's very controversial in the climbing world, especially in areas like Fontainebleau. This is because POF leaves a residue which then hardens and creates a greasy glassy coating on the rock. This coating effectively ruins the route for others by destroying any natural friction from the rock’s surface, and if you’re using POF, the only way around it is to use more POF. It’s because of this cycle that climbing chalk is largely seen as a much less damaging option, with responsible brushing, it’s easier to remove excess chalk and leave the rock un-damaged and mark-free. 


A close up of a box filled with lumps of white magnesium carbonate climbing chalk

With all this talk about chalk, you might be thinking we’re talking about the white cliffs of Dover or the stuff people use to draw on blackboards. But when climbers talk about chalk we’re actually referring to a substance called Magnesium Carbonate. Unlike chalk, which is now mostly made from Calcium Sulphate or Gypsum, Magnesium Carbonate (MgCO3) is actually an inorganic salt, which is usually obtained by mining the mineral Magnesite, although it can also be produced in a lab. It has many industrial uses, but the one we're interested in is its capabilities as a non-toxic drying agent. This is where it becomes massively useful for climbing and grippy sports such as weightlifting and gymnastics. 


In short, the vast majority of climbing and gym chalk is mined and refined from a mineral called Magnesite, deposits of which can be found across the globe, although China is easily the world's biggest producer. Magnesite’s chemical composition is the same as magnesium carbonate, MgCO3 but it needs to be processed in order to produce the powder we fill our chalk bags with. This process involves crushing and purifying the Magnestite using acid baths and baking soda, and then drying it to produce the MgCO3 powder. But climbing chalk is not the only use for Magnesite which is the main source of the world's magnesia. Estimates suggest that two-thirds of the world’s magnesium comes from intensively mined magnesite, and it’s big business, fueling a wide variety of industries, from aviation, farming and pharmaceuticals.

The damaged landscape surrounding Jelsava-Lubenik magnesite mine in Slovakia

Jelšava-Lubeník Magnesia Mine, Slovakia. Courtest Google Maps


Given the high demand for such a sort after mineral, of which the sports industry makes up a small section, it’s probably no surprise that such an intense mining and purifying process comes with a heavy environmental price. Mining can never really be called sustainable, as you’re irreversibly depleting the earth’s resources, and although there is estimated to be enough Magnesite to last hundreds of years at our current consumption, the real problem here is the processes used to extract and refine climbing chalk, and other magnesium substances. 


The science on the effects of Magnesite mines on the surrounding environment makes for worrying reading. One study conducted by Juraj Fazekaš et al on the environment around Jelšava-Lubeník in Slovakia, one of Europe's largest Magnesite mines, found a “negative impact on the basic elements of the environment”. The devastation around the plant is easy to observe, with waste dumps and craters from surface mining scaring the landscape, and the pollution goes much deeper than just physical. Dust from the mining process coats the soil in the area, significantly reducing vegetation growth and causing “chemical intoxication, and soil devastation.” The shocking conclusion of the study rated the environmental diversity of the area as “extremely low (0.0) to middle low (1.5)” on the Shannon index. Given, that this is just one site of many around the world it’s safe to assume, although some will be more responsible than others, that mining magnesite is currently a damaging industry for the planet.

A Vast White Scar on the Landscape around Xiafangshen Magnesium Mine in China

Xiafangshen Magnesium Mine, China. Courtesy Google Maps


With such a high environmental cost related to the mining of climbing chalk, you’re probably wondering what the best way to negate this is. Well, there are some things you can do besides simply not using chalk.


It may seem a bit of an obvious one, but using a little less chalk can go a long way to reducing the demand for mined chalk and it can also have a positive effect on the rocks we love to climb. Using a smaller amount of chalk by switching to a chalk ball, or just not digging as deep in your bouldering bucket means less excess chalk dust left on the rock. Even if you’re a thorough brusher, little steps like this can make a difference.


You may have noticed that some climbing & bouldering shops have started selling chalk that doesn’t come from digging a big hole in the ground. Instead, it is produced sustainably by refining byproducts from seawater desalination processes which would otherwise go to waste. It’s a bit of a home run, as there’s no dust from mining, no physical scarring to the landscape and the resulting climbing chalk is naturally much purer than other mined versions and it doesn’t have to undergo intense chemical purification. Here at Psychi, we’re making the move to sustainable seawater-derived climbing chalk by developing our totally sustainable Psych Powder

A beach on the Ardnamurchan penninsular in Western Scotland. The word psychi is written in the sand


Basically an antiperspirant for your skin Antihydrals are a fairly recent addition to the climber's sweat-reduction arsenal and have been praised by some top climbers. Although they can be very effective and definitely reduce the need for chalk they are a risky thing to use if your skin is naturally dry as the effect can cause cracking and irritation and lasts a few days. Learn more about Antihydrals below.


Given the problems mentioned above, it’s fair to ask why we even need chalk. We all know that even watching someone climb can give you sweaty palms. (Free Solo should be viewed with a towel). So when it comes to a big bouldering session or a long trad climbing route, we need to keep that sweat in check if we want to perform at our best and avoid pinging off everything. It all comes down to friction, sweat means less friction which means less effective grip. Magnesium Carbonate crystals absorb the sweat on your hands and they’re abrasive, giving you more friction and an uncompromised grip.

Psychi athlete Max Milne Bouldering at Last Sundance Climbing Centre in Leeds


So some big claims are being made, and although chalk is now commonplace in the climbing world, it's best not to just (incoming dad joke) ‘brush over’ the science here and ask if anyone’s actually put climbing chalk to the test. 


Most climbers will tell you that they experience a notable increase in the amount of friction they’re getting when using chalk vs not using chalk. But as this kind of evidence is anecdotal, we need to dig a bit deeper. 

Research focused specifically on climbing can be hard to find, but there are some good climbing-centric studies that do show a marked increase in performance for things like hang time, coefficient friction, and grip when climbers use chalk (100% Magnesium Carbonate). 

A climbers hands, covered in chalk crimping on a thin ledge


In their 2018 study published in the international journal of exercise science Bacon et al set out to discover if the use of chalk increased climbers' performance during open-handed and pinch grip weight-assisted pull-ups. After testing 9 experienced male climbers, their research found a marked increase in the number of pull-ups, both open-handed and pinch grip, the participants were able to achieve when using climbing chalk. So that indicates a big tick for an improved grip.


Published in Sports Biomech in 2012 Amca et al studied 11 climbers and tested their ability, with and without chalk, to hang from sandstone and limestone holds at increasingly extreme inclinations until their hands slipped. After 42 sessions the researchers conclude, “that there was a significant positive effect of chalk on the coefficient of friction (+18.7% on limestone and +21.6% on sandstone)” which is quite a significant result. 


In 2016 M A Kilgas et al tested the hang time of 19 climbers (13 males, 6 females). Each participant completed 2 trials hanging from a standard climbing hold, with and without using climbing chalk until their grip failed. Publishing their results in the Journal of Applied Biomechanics Kilgas et al found that “participants were able to hang longer after the use of chalk” and concluded that using magnesium carbonate was of great benefit to climbers as it would allow them a prolonged rest when hanging.

Joe Swales bouldering on an overhang in Rocklands, South Africa

Given this research, and the anecdotal evidence of the vast majority of climbers I think it’s safe to say that climbing chalk is here for a reason and the knock-on effects of improved friction are pretty clear. If using chalk means you can hang longer and pull harder you’re going to see a pretty significant improvement in your climbing. 


When it comes down to it, the best climbing chalk can be a pretty subjective issue. Everyone will have a consistency preference and some prefer liquid chalk to chalk powder. Luckily you don’t need to steal a bear’s breakfast to test which chalk works for you, but a bit of Goldilocks esque trial and error is the best way to go to find the right fit for you. Here are a few pointers to get you on your way:


The most simple form of climbing chalk is the classic bag of loose powder. Some like it hard, some like it soft, some like it lumpy and some like it super fine. The right consistency for you will depend. Factors as simple as how it feels to apply can tip the balance, some climbers like to crush lumpy chalk in their hands and will say they get better coverage that way, whereas others prefer fine powder because it’s smoother and has a smaller particle size.

Some companies use extra drying agents in chalk, these will dry your hands out more than just pure magnesium carbonate and can therefore give you a better grip, but they can also throw up problems if you already have naturally dry skin, causing irritation and cracking.


We think it's the most versatile of all, given you can add as much or as little as you want to your chalk bag and you can share it with friends or use it to refill refillable chalk balls. 


It can get messy, we’ve all kicked over a bouldering bucket or dropped a newly filled chalk bag, and it's a faff to try and scrape it all back in, you never quite get it all, especially if you’re using a finer powder. Also, it's easy to create dust simply by applying finer loose chalk.


Liquid chalk contains the same magnesium carbonate as powder chalk, but it's suspended in alcohol. When rubbed onto your hands the alcohol evaporates taking moisture from sweat with it, leaving your hands dry and perfectly covered in chalk.

A climbers hand covered in liquid chalk


Reduction of dust is a major one, as it’s suspended in a liquid applying it doesn’t produce clouds of dust like loose chalk or chalk balls.

Liquid chalk is often way easier to store and transport, as it comes in a resealable bottle.

Because it’s rubbed in as a liquid the chalk tends to get into all the minute folds and cracks on your hands and therefore tends to last longer.

You’ll probably have noticed more people using liquid chalk during covid, and that’s because it does have antibacterial effects. Although the alcohol content is usually lower than hand sanitiser it's more or less the same stuff.


There are a couple of downsides. It's easy to over-apply and difficult to only apply to specific areas on your hands. 

It's difficult to apply if you’re halfway up a long sport climb as you’ll normally have to squeeze it out of a bottle.

Because of the alcohol, it can dry your skin out more, causing cracking after prolonged use. It's also worth checking the ingredients of any liquid chalk, some have additives that can cause irritation, especially for broken skin. Try applying it when you haven’t noticed a flapper or a scraped finger, and you’ll immediately know what I mean! 

Some liquid chalk contains resin, which is used to thicken the consistency and make the chalk feel more sticky. If you don’t let the liquid chalk completely dry resin like this can leave a residue on rock and climbing holds which is really tough to remove and essentially ruins them. This was a real problem for centres during covid, so make sure your hands a try before pulling on!


Ahh the good old chalk ball. Again, chalk balls contain magnesium carbonate, although it's usually a much finer consistency. This is because it’s contained within a porous cotton mesh which releases a smaller amount of chalk with every squish, pat or squeeze. 

A climber's open hand holding a climbing chalk ball


Chalk balls are a great way to reduce chalk waste as they only let out a little bit each time without producing big plumes of dust.

Most climbing shops will sell refillable chalk balls, which is a great way to reduce waste. One thing to bear in mind though, is you need to crush any lumpy loose chalk a bit before you fill one. This helps maintain the cotton mesh and allows chalk to pass through as normal.


Chalk balls only let out a small amount of chalk, so if you have sweatier palms, or you just like more chalk they might not be the best for you.


A boulderer breaking a chalk block into a bouldering bucket at Rockover Climbing Manchester

A chalk block is simply fine magnesium carbonate that has been heated and compressed before it was dried. Creating a solid block of chalk. 


By using the edges to apply chalk to quite specific areas on your hands you can waste less and be really accurate, giving your grip a boost only where you need it.


It can be messy to transport without a sealed container, and if it breaks you’re basically left with lumpy loose chalk.


A climber rubs his hands together with chalk before tackling a bouldering problem at Rockover Climbing, Manchester


In short, they aren’t. A lot of brands will talk about their own particular niche, be it the chalk’s origin, added drying agents, essential oils, scents and even in some cases extracts that can make your hands feel warmer or colder, so there’s a lot out there, and without trying them all it's hard to tell which will be the best for you. At Psychi we like to keep it simple and don’t add anything to our chalk. 


With such a huge range of chalk and drying methods out there, the best starting place for any climber is to pay attention to your skin's natural moisture levels.


If you have naturally dry skin it's best to be careful with liquid chalks, antihydrals, or loose chalk with added drying agents such as silicon or upsalite as they can really strip away what little moisture you already have, causing irritation and painful cracking.


If you naturally have sweaty tips the opposite can be the case, and you might find that regular chalk doesn’t come close to curbing the moisture on your hands when you’re climbing hard. In this case, looking for chalk with extra drying capabilities or even an antihydral could make a big difference to your climbing.


Lots of brands will sell chalk in different consistencies. They might have fancy labels and names, but really, other than the amount it has been crushed the chalk is the same, unless it states different additives. There are only really two consistencies for loose chalk; Lumpy or Fine.


Brands will always talk about what is or isn’t in their chalk. But to keep yourself covered it's always best to read the label to find out what’s actually in the bag. Extra drying agents, bulking agents and other additives can sometimes cause irritation, and if you’re breathing in dust when you chalk up it's best to get a chalk that states there are no heavy metals or other nasty stuff present.


Read what others are saying. Getting a general consensus from people who have already tried and tested a brand’s chalk is super useful. Even reading bad reviews can give you a good idea of how the chalk performs, what quality you’re likely to get and whether it’s likely to suit you.


The question of whether chalk should be used outside is still somewhat of a discussion in the climbing world. Chalk is now so pervasive it's hard to imagine the sport without it, but there are some problems with using it on real rock.

Psychi athlete Martin Heald reaching his hands into a chalk covered crack on a massive boulder in Fontainebleau 


It’s happened to us all, we’ve all turned up at a crag or bouldering spot and found chalk left on holds and even tick marks from the last person who tried the route you have planned. It's not only the ruined aesthetic of the rock being covered in marks, but leftover chalk absorbs moisture and dirt, making holds slippery, and leaving you with a clean-up job before you can climb.


Brushing excess chalk from holds and dusting down tick marks preserves the aesthetic and quality of the rock making it feel untouched and clear for the next person to climb. Make sure you use a climbing brush with soft bristles, especially on softer rock.


Coloured Chalk has been developed in America for use in national parks where the use of white chalk has been banned. It is billed to help blend chalk marks into the natural rock's colour, however, its effectiveness is pretty limited, as we all know all rocks are different colours, and matching a chalk’s colour to the rock you want to climb is next to impossible without turning up to the crag with a colour chart from B & Q and a van full of chalk.


A boulderer removing his chalky hands from a bouldering bucket at Rubicon Crag in the Peak District


As I mentioned above Antihydrals are grabbing the attention of climbers more and more and are definitely an option for climbers with particularly sweaty tips. But the way they work is quite extreme and the effects last a long time, making them difficult to recommend to everyone.


In short, it’s probably a no. There are side effects for people who are allergic to formaldehyde and if used too much by someone with naturally dry skin, painful cracking can occur. If you’re going to try it out, it's best to use a little bit on a small area of skin first, and then wait a few days.


Basically, an antihydral is an antiperspirant for your skin. They work using an ingredient called Methenamine which reacts with the natural acidity of your skin, producing formaldehyde which denatures the proteins in your pores forming a blockage against sweat. The effect can last up to three days, which makes it a useful option if you’re on a big climbing trip, but a pretty extreme one if you’re just climbing for a couple of hours. You’ll also need to apply the antihydral a couple of days before you climb for it to be effective. 



Washing chalk from your hands when you’re done climbing is important for your skin’s recovery. Thoroughly washing your hands stops climbing chalk from absorbing moisture and natural oils on your hands that help your skin naturally repair after a big session.


Moisture isn’t something most climbers want on their hands, and as discussed above, there’s a whole industry aimed at taking it away while you climbing. But using moisturisers and natural hand balms after you climb really helps your skin recover. By holding moisture and replacing essential oils stripped away by chalk and Antihydrals a good skin repair balm gives a huge leg up for your skin’s natural healing process, and will get your skin ready for the next climb faster.


Despite its rather conspicuous appearance, you can take it on a plane in your baggage, even if you’re on your way back from Columbia.


Magnesium Carbonate is non-toxic and is used in some pharmaceuticals as a treatment for indigestion. So if for some reason you ingest some, you don’t need to worry. Aside from potential laxative effects if you decide to really chow down you’ll be fine.

If for some reason your dog decided it had a taste for chalk (be honest they’ve done weirder things) and really went to town, it’s best to seek the advice of a vet.


Believe it or not, this article was written by an actual human. Which means I’ve probably made mistakes and voiced opinions some will find controversial. Chalk has become a nuanced subject, and everyone will have their two cents, so let us know in the comments what you think, it’s all useful information that someone might find helpful!




  1. Fazekaš,J.,Fazekašová,D.,Hronec,O.,Benková,E. & Boltižiar,M.(3918).Contamination of soil and vegetation at a magnesite mining area in Jelšava-Lubeník (Slovakia). Ekológia (Bratislava),37(2) 101-111.
  2. Bacon, Nicholas T et al. “Effect of Magnesium Carbonate Use on Repeated Open-Handed and Pinch Grip Weight-Assisted Pull-Ups.” International journal of exercise science vol. 11,4 479-492. 1 Jan. 2018
  3. Amca, Arif Mithat et al. “The effect of chalk on the finger-hold friction coefficient in rock climbing.” Sports biomechanics vol. 11,4 (2012): 473-9. doi:10.1080/14763141.2012.724700
  4. Kilgas, Matthew A et al. “The Effect of Magnesium Carbonate (Chalk) on Geometric Entropy, Force, and Electromyography During Rock Climbing.” Journal of applied biomechanics vol. 32,6 (2016): 553-557. doi:10.1123/jab.2016-0009

Older Post
Newer Post

Leave a comment

Please note, comments must be approved before they are published

Back to top

Added to cart