What Are Climbing Holds Made Of: Materials Explained?

A hold that feels slick on a humid day and one that bites like sandpaper can come off the same wall — the difference starts with the recipe poured into the mold. No single material rules the market: modern gyms mix polyurethane on steep sections, polyester on slabby stuff, and fiberglass behind the biggest volumes.

The Five Materials Behind Every Climbing Hold

Holds are made from polyurethane, polyester resin, fiberglass, wood, or ABS thermoplastic, with the first two covering most of what you’ll touch in a gym. EP Climbing, which sells holds across several material lines, builds its ranges around these categories rather than one universal compound.

Polyurethane (PU) is the modern standard. EP Climbing describes PU as light and impact-resistant, which is why it dominates new gym sets — a dropped hold is far less likely to chip.

Polyester resin is the traditional option. EP Climbing calls polyester a classic resin and notes its dry, abrasion-resistant texture — the quality that keeps it on gym walls year after year. Where PU holds up to impact, polyester holds up to friction and wear.

Fiberglass shows up mainly in macros and volumes, the oversized pieces that frame a wall. Some macros use high-grade fiberglass for strength without much weight — the point when bolting a four-foot feature overhead.

Wood plays a smaller but real role in volumes and home walls, where texture and cost matter more than weather resistance. ABS thermoplastic covers the rest — some grips combine polyurethane and ABS, common in entry-level and kids’ lines.

What Actually Changes Between Hold Materials

Material choice comes down to the purpose, size, and function of the grip, and the practical differences show up in feel, wear, and weight rather than any single spec sheet.

Hardness is measured in Shore D and jumps around by manufacturer and product line. Recycled and bio-based content varies just as widely: some PU carries 40% recycled raw material, and some BioResin mixes hold about 30% biocontent.

Mounting and compatibility follow the product type, not the material name. A brand might pour PU and wood in the same catalog, or mix a fiberglass macro with PU bolt-ons, so what threads onto your wall depends on the specific piece and its intended use. Different brands also run different factories and materials, so no single name guarantees one compound across every product.

Alumilite’s overview of climbing hold applications makes the same point from the manufacturing side: several resin systems get poured depending on the finish and toughness a maker wants, rather than one mix serving every product.

If you’d rather skip buying blind, a tested roundup of climbing holds walks through what holds up on a home wall and what doesn’t.

Rampf’s tooling page adds a detail worth knowing: production methods differ between resin-based and thermoplastic holds, and that process difference influences density and surface finish. Two holds labeled the same material can feel worlds apart if they came out of different molds on different equipment.

Weighing texture, weight, and wear against where you’ll bolt your holds is the only way material choice pays off. EP Climbing’s hold collection organizes its catalog by these material lines, giving you a real reference point for how each type is sold.

The takeaway: polyurethane for durability and light weight, polyester for grip and wear resistance, fiberglass for big features, wood for texture and home setups, and ABS for budget builds.