Climbing Brushes

Big, Small, or Medium Brushes, you can use toothbrushes, nail brushes, or even dish brushes. Or, you can try slapping a cloth onto the holds you want to climb.

Table of contents

As you progress in climbing, you’ll eventually realize that having just a little more grip can help you hold on for a second longer and reach the next hold.

It doesn’t really matter what you use to brush the holds—most brushes will help you increase friction. So make sure to include at least one in your bouldering gear. This article provides some considerations for buying and using brushes or other cleaning tools.

Fictional climbing brushes

Is Brushing Effective?

Yes, brushing can often make a difference, especially on slopers and small crimps. Many times, I’ve noticed brushing helps me find that little extra grip to get to the next hold. However, I’ve also learned not to overestimate its effect.

I’ve seen experienced climbers hold onto holds I couldn’t manage, even after brushing them. For me, brushing is often more psychological—it helps me mentally prepare for the ascent. So yes, it’s effective, but don’t be surprised if more experienced climbers send your project without any brushing at all.

Using Climbing Brushes Outdoors

When bouldering outdoors, it’s important to consider the type of rock you’re climbing on. Sandstone, for example, is one of the more fragile rocks. Brushing can have an impact on holds, which is why some boulderers avoid using chalk or brushes altogether. I’ve even had a few people give me angry looks for using them!

Some climbers believe that slapping holds with a cloth is less harmful than brushing. Ultimately, the key to outdoor climbing is to be as respectful as possible to the boulders. Always aim to leave the rock as clean as you found it.

When it comes to brushes, many brands advertise soft bristles (Boar’s Hair). I recommend using these on soft rock like sandstone to minimize wear.

Impact of brushing outdoors

In 2025 a scientific article showed the impact of climbing and brushing on vegetation of boulders. Using 3 unclimbed boulders (sandstone, limestone and granite) they measured the impact on vegetation ((mosses and their relatives) of cleaning and climbing it. Sandstone suffered most by losing most vegetation. On average the boulders would lose about 15% of its vegetation. Additionally the researchers also observed that microplastics would remain on the boulders. 

We did not need scientific evidence that climbing and removing vegetation would have an impact on nature. But with this article nobody can deny the facts. 

So please when bouldering or climbing in nature: 

  • Before climbing: Brush for your own benefit before climbing
  • While climbing: Brush and clean your shoes, for your own benefit (no slipping) and for the benefit of nature (leaving less microplastics)
  • Before leaving: Brush and leave a clean boulder for nature and the climbers coming after you

Brushing to Explore the Climb

Personally, I enjoy brushing holds—not just to make them less slippery, but also as a way to explore the climb. Brushing gives me a chance to take my time and study the holds. It provides valuable clues about their shape and helps me visualize how to grip or stand on them. It’s also a great way to discover all the holds on a route, helping me prepare for the climb in the most optimal way.

Brushing for Indoor Bouldering

When it comes to indoor bouldering, brush as often as you feel like it. I’ve seen people use everything from dish brushes to shoe brushes and even toothbrushes. Many climbing stores sell specialized brushes, but do they really offer something better than what you can buy at a supermarket? In my experience, not really.

Big or Small Brushes?

If you’re a beginner climber, a bigger brush will usually be enough. As you progress to higher grades, the holds will become smaller and harder to reach. At that point, smaller brushes will be necessary to clean those tiny surfaces effectively.

Buying Brushes (If You Have To…)

  • Materials:
    • Boar’s Hair: Soft and best for fragile rock like sandstone.
    • Nylon: More durable.
    • Synthetic: The most versatile option.
  • Handles: Brushes come with straight, angled, or telescopic handles, each serving different purposes.
  • Sizes: Brushes are available in a variety of sizes to suit different needs.

Brush Before Leaving

Especially when climbing outdoors, always leave the boulder problems as you found them. Before you leave, brush the holds to ensure the area is clean and preserved for future climbers.

Sources