Outdoor bouldering etiquette

Rosin is sticky. It pulls chalk deep into the rock’s pores and micro-cracks, then hardens into a glossy, sealed film. That film changes the hold’s texture and friction forever. Rain cannot wash it out cleanly; instead it drives more residue deeper into the stone. The rock is damaged beyond repair.

Some commercial products — including certain Mammut liquid chalks and other brands — add rosin or resin for longer adhesion. That may feel helpful indoors, but outdoors it permanently scars natural rock. Never bring it to the crag or use it on real rock.

Be careful with liquid chalk that lists ingredients only as “その他” (other). Vague labels can hide resins, binders, or additives that damage rock. If you cannot confirm the formula is pure chalk (magnesium carbonate) without resin, do not use it outdoors.

Using rosin chalk is not a personal preference — it steals the problem from every climber who follows and shows disregard for nature. Respect the rock.

Brush holds between tries so chalk does not cake into the texture. Brushing also removes bits of shoe rubber left on the rock — that rubber polishes holds and makes them slicker over time. Clean rock climbs better and stays healthier.

Wipe your shoes and keep the soles clean between tries. Dirt, chalk, and rubber stuck to your shoes get ground into the holds and polish the rock further. Clean shoes protect the stone as much as a clean brush does.

Before you leave, brush and clean the rock thoroughly — even if someone says they will clean it later. Own the mess you made. Do not leave chalked holds for the next party or for rain to work into the stone.

Chalk buildup also damages rock over time. Left on the rock, it cakes into a hard crust that is much harder to clean later and leaves unpleasant white streaks across the stone. When it rains, water carries chalk into cracks and pores in the holds. As moisture cycles and residue expands and hardens, holds can glaze, polish, or weaken. Brushing is rock care, not just aesthetics.

Tick marks are fine when you need them — keep them small and precise. Brush them off completely when you are done with the problem or before you leave.

When rock is wet, chalk and dirt wash straight into cracks and seams. That residue can start to loosen holds, and as it dries it leaves a stubborn film that changes friction and texture. Wet climbing also polishes and loads weakened stone, so features that felt solid can fail. Wait until the rock is fully dry — for the rock, for access, and for the climbers who come after you.

Say hello when you arrive. If you want to climb in the same area or on the same boulder, ask to session rather than assuming space is free. When you are about to use another person’s mat for the first time, say 「マットお借りします」 (mat-toh oh-kah-ree-shee-mahs) — “I’ll borrow your mat.” Be aware of turn-taking, noise, and how many pads are already in play.

Follow Leave No Trace principles: stay on established approaches where they exist, keep noise down near houses and trails, and leave plants, soil, and wildlife undisturbed.

Do not leave other people’s garbage behind either. Even if the trash is not yours, do nature a favor and pack it out when you can. Leaving it for “someone else” only means it stays in the woods.