Objectively testing chalk is no easy task. Variables like temperature and humidity affect friction and performance outdoors as well as indoors, plus many of our testers had conflicting opinions about what makes good climbing chalk. Some testers like there chalk in a fine powder that cakes up on their hands. Others preferred a thin layer of chalk that doesn't build up on the climbing holds. This led us to choose metrics that would highlight the differences between each product, so you can make better chalk choices based on your personal preferences, or if your new to the game and don't know/care what type of chalk you use, you'll have plenty of food for thought when it comes to buying chalk.
Friction & Overall Feel
This was the most difficult metric to get hard numbers on, and we relied on our testers' daily experience with each chalk to decide which chalk performed the best. Our testers have been climbing and using chalk for years (decades even), and many already have solid preferences towards a particular brand of chalk. For this reason, we put the loose chalk in numbered plastic bags so testers would have no idea which chalk they were using, and had them perform a series of hangs on the hangboard, including slopers and crimps, climb around the gym for a while and then answer our questions about feel and friction.
We measured coverage in two ways. First, we'd make our testers rub a tablespoon of chalk into their hands, and we'd take a hi-res photo. Then we'd have them perform three reps of 20-second hangs on the same freshly brushed slopers in the gym. Then we'd take a second photo and compare it with the first, noting how much chalk was left on our testers' hands. For the chalk balls, we performed an additional test by dropping each ball on black foam board and looking at how much chalk was forced through the cloth.
For this metric, we looked at how much chalk was ending up on the ground when our testers transferred chalk from its original packaging and into their chalk bags and buckets. We also observed (but not measured) how much dust each product appeared to create.
Value isn't usually assessed in our scoring systems, but we made an exception for chalk since so many aspects that make for good performance seem so subjective. We broke down each product by price per ounce based on the best deal offered on the manufacturer's websites.
Our testing occurred at the local bouldering gym and the world-class crags and boulders surrounding Bishop, California.