ForMatter/Materials/other/Natural Cork
mat_cork_natural

Natural Cork

plant-bark cellular biomaterial · cork bark, Quercus suber bark, wine-bottle cork material
highlast updated 2026-04-26

The bark of the cork oak (Quercus suber), harvested without killing the tree on a roughly nine-year rotation. A natural closed-cell foam: light, springy, water-resistant, and one of the few materials that recovers fully from compression without losing memory. Wine corks, flooring, gaskets, surf-board cores, sneaker soles.

Natural closed-cell biological foam — ~14-sided polyhedra, ~40 µm cell size, walls 1–1.5 µm thick. Suberin and lignin make the cell walls hydrophobic and chemically inert. Density ~120–240 kg/m³. Compressive Poisson ratio ≈ 0 — cork compresses without expanding sideways, which is why a wine cork can be pushed through a smaller-diameter neck.

Mechanical

  • density · kg/m³160
  • compressive strength · kPa700
  • Young's modulus · MPa20
  • Poisson ratio0
source: Pereira, Cork: Biology, Production and Uses (Elsevier 2007)

Thermal

  • thermal conductivity · W/m·K0.04
  • service max · °C200

Sustainability

  • embodied carbon · kg CO₂e/kg0.2
  • recyclabilityhigh — fully biodegradable; cork forests are net carbon sinks while in production; bark regrows on the same tree
  • biodegradableTrue
  • certificationsFSC
  • localityMediterranean basin — Portugal alone produces ~50% of world supply; Spain, Algeria, Morocco, Italy follow
source: Editorial estimate from ICE / Granta CES EduPack class databases — industry mean, with cradle-to-gate boundary unless otherwise noted. Embodied carbon for any specific product depends on supplier mix, recycled content, and energy grid; verify against a primary source before using these numbers in a sustainability claim.
visual
tan to brown, mottled with fine pores, distinctive cellular pattern visible on cut faces
tactile
warm, dry, slightly grippy, springs back under thumb pressure
weight perception
very light
acoustic
absorbs sound; subdued tap

PBR starter values

finish · granular — open for table, JSON, host snippets, downloads

Principled BSDF defaults derived from the sphere granular finish. Reasonable seed for Blender, Substance, Keyshot, Rhino — tune per material. Or grab the whole library at once: ForMaterials library →

# finish:                   granular
albedo                      #c8a070
metallic                    0.00
roughness                   0.85
ior                         1.45
transmission                0.00
clearcoat                   0.00
sheen                       0.00
anisotropic                 0.00
copy as JSON 
{
  "albedo": "#c8a070",
  "metallic": 0.0,
  "roughness": 0.85,
  "ior": 1.45,
  "transmission": 0.0,
  "clearcoat": 0.0,
  "sheen": 0.0,
  "anisotropic": 0.0
}
Blender 4.x Python 
# Blender 4.x — Principled BSDF
# Natural Cork · finish: granular
import bpy
mat = bpy.data.materials.new(name="mat_cork_natural")
mat.use_nodes = True
bsdf = mat.node_tree.nodes["Principled BSDF"]
bsdf.inputs["Base Color"].default_value         = (0.5776, 0.3515, 0.162, 1.0)
bsdf.inputs["Metallic"].default_value           = 0.000
bsdf.inputs["Roughness"].default_value          = 0.850
bsdf.inputs["IOR"].default_value                = 1.450
bsdf.inputs["Transmission Weight"].default_value = 0.000
bsdf.inputs["Coat Weight"].default_value        = 0.000
bsdf.inputs["Sheen Weight"].default_value       = 0.000
bsdf.inputs["Anisotropic"].default_value        = 0.000
KeyShot Python (lux) 
# KeyShot 11+ — lux Python API, Generic material
# Natural Cork · finish: granular
# Run from Window → Scripting Console
import lux
mat = lux.createMaterial(name="mat_cork_natural", materialType="Generic")
mat.setProperty("diffuse",      (200, 160, 112))   # 8-bit sRGB
mat.setProperty("metallic",     0.000)
mat.setProperty("roughness",    0.850)
mat.setProperty("indexOfRefraction", 1.450)
mat.setProperty("transparency", 0.000)
mat.setProperty("coatingWeight", 0.000)
Substance pbrMetalRough 
{
  "_format": "Substance Designer / Painter \u2014 pbrMetalRough constants",
  "_about": "Natural Cork \u00b7 finish: granular",
  "baseColor": {
    "r": 0.5776,
    "g": 0.3515,
    "b": 0.162
  },
  "metallic": 0.0,
  "roughness": 0.85,
  "ior": 1.45,
  "opacity": 1.0,
  "anisotropyLevel": 0.0,
  "_notes": "Channels listed are the standard Substance pbrMetalRough output. Drop into a Uniform Color node per channel, or as the constant input on a layered stack."
}
glTF 2.0 Metallic-Roughness 
{
  "asset": {
    "version": "2.0",
    "generator": "ForMatter"
  },
  "materials": [
    {
      "name": "mat_cork_natural",
      "pbrMetallicRoughness": {
        "baseColorFactor": [
          0.5776,
          0.3515,
          0.162,
          1.0
        ],
        "metallicFactor": 0.0,
        "roughnessFactor": 0.85
      },
      "extensions": {
        "KHR_materials_ior": {
          "ior": 1.45
        }
      }
    }
  ]
}
USD Preview Surface 
# USD Preview Surface — UsdShade.MaterialLook prim attributes
# Natural Cork · finish: granular
def Material "mat_cork_natural" {
    token outputs:surface.connect = </mat_cork_natural/PreviewSurface.outputs:surface>

    def Shader "PreviewSurface" {
        uniform token info:id = "UsdPreviewSurface"
        color3f inputs:diffuseColor = (0.5776, 0.3515, 0.162)
        float   inputs:metallic     = 0.000
        float   inputs:roughness    = 0.850
        float   inputs:ior          = 1.450
        float   inputs:opacity      = 1.000
        float   inputs:clearcoat    = 0.000
        token   outputs:surface
    }
}
↓ download glTF material
ProcessLaser Cutting · CNC Milling · Adhesive Bonding
Substitutes
Mycelium Composite (Grown)

Second life

repairabilitymoderate — cork accepts adhesive repair; the wine-stopper tradition replaces rather than repairs.
recyclabilityvery high — cork is fully biodegradable; closed-loop wine-cork-recycling programs (ReCork) exist.
disposal pathcompost; specialty cork-recycling programs.
typical longevity50 years (typical)
failure modes
  • compression-set under sustained load
  • desiccation cracking in dry storage
  • mold in damp conditions (the canonical "corked" wine-bottle failure)

APCOR Portuguese Cork Association technical literature; ReCork by SOLE recycling-program documentation.

Citations