Magnesium carbonate (MgCO3) has long been used by gymnasts to improve their grip on bars, rings or vaulting horses. Climbers, too, use chalk for keeping hands dry and holds secure when climbing indoors and out.


A variety of chalk, bags and accessories are available to climbers. What you select will depend on your climbing style and the environment.

This article provides you with quick shopping assistance.

Chalk

Block, Bulk or Ball?

Chalk ball

  • Block chalk, or compressed magnesium carbonate, is standard gym chalk and is widely used for all outdoor rock climbing styles and venues. It provides friction and moisture absorption and is the least expensive variety.
  • Loose bulk chalk is the workhorse for long outdoor routes. Fill up a large bag with the stuff and you'll be able to chalk up repeatedly all day. Some types of loose chalk are available with an added drying agent to absorb moisture for better gripping ability.
  • Chalk balls are sacks made of porous fabric filled with loose chalk. The sack keeps chalk dust contained in the bag as you apply it to your hands and prevents you from spilling it and breathing it. They are the cleanest and healthiest choice for indoor climbing, and they last longer than loose chalk.

Chalk Colors

Most chalk is white, but some varieties are available in colors to match the rock, leaving less of a visual impact. Some other types of so-called "chalk" are actually drying agents without color. They leave no trace on the rock.

Chalk Bags

Sizes

Chalk bag

Chalk bags come in a few sizes:

  • Smaller bags are used by climbers with smaller hands or for anyone coating only their fingertips or a portion of their hands (such as on steep sport climbs).
  • Larger bags are practical for any climber, but especially if you have larger hands or are climbing long trad routes where you're coating the entire hand or even a portion of the arm (think wide cracks).
  • Buckets are larger still, best suited for group bouldering sessions where you use a lot of chalk. You don't wear these on your waist; rather, they are placed on the ground for pre-climb "dips."

Shapes

Bags worn around the waist typically come in 2 shapes. Cylindrical bags usually hold more chalk and are good for longer climbs; tapered styles are suited for shorter sport routes. Some bags are flat on one side so they hang flush to the climber's body.

Expert Tip: An alternative to a chalk-bag belt is a length of tubular 9/16” tubular webbing tied at the waist with a water knot. This “belt” offers the bonus of a harness backup and a spare runner. The webbing must be threaded through the harnesses tie-in loop and should have an adequate tail at both ends. Heidi Pesterfield, author of Traditional Lead Climbing.

Features

  • Stiffened rim: Holds the bag open for easy dipping.
  • Fleece lining: Holds down the chalk dust and distributes the chalk evenly on your hands.
  • Cord and toggle closure: Keeps chalk from spilling when not in use.
  • Chalk bag belt: Secures bag around waist and allows you to slide it either front or rear for easy access.
  • Toothbrush loop: Accommodates a toothbrush to clean old chalk off holds.
  • Zippered bottom pocket: Holds a gel packet or car keys.

Shop REI's selection of chalk and chalk bags.

Article contributor: Heidi Pesterfield, climber and author of Traditional Lead Climbing by Wilderness Press.