ForMatter/Materials/ceramic/Stoneware Clay
mat_stoneware

Stoneware Clay

ceramic — vitreous high-fire body · stoneware, high-fire clay, cone-10 stoneware
mediumlast updated 2026-04-27
metallic 0.00
hue shift +0°

The clay between earthenware and porcelain. Fires at high temperature into a dense, dark body that holds water without a glaze and rings when tapped. The default workshop clay in any ceramics studio that throws — tougher than earthenware, more forgiving than porcelain.

Plastic clay body, typically a blend of fireclay, ball clay, and feldspar, fired to vitrification at cone 5–10 (~1200–1280 °C). Body color ranges from buff to red-brown to dark gray-brown depending on iron content. Water absorption < 3% post-fire — functionally non-porous without glaze. Compressive strength ~250 MPa fired; modulus of rupture 30–60 MPa.

mechanical

  • modulus_of_rupture_mpa45
  • compressive_strength_mpa250
source: Digitalfire stoneware references

thermal

  • firing_cone10 (~1280 °C)
source: studio practice

physical

  • density_kg_m32300
source: Wikipedia — Stoneware

Sustainability

  • recyclabilityhigh pre-fire — dry trimmings rehydrate forever; post-fire is permanent and inert
  • biodegradableFalse
  • certifications—
visual
buff to dark brown unfired; varies from speckled tan to dense brown to gray-brown when fired; glaze color depends on body underneath
tactile
cool, smooth-when-burnished, slightly grainy at unfired tooth
weight perception
heavy
acoustic
a clear ring when fired — the unmistakable sound of vitrified ceramic
Sōetsu Yanagi (dead — channeled)

The country potter does not sign the bowl. The bowl will be used a thousand mornings and the maker's name will not survive any of them — and that is exactly the right ratio. Stoneware is the material that lets a workshop do this. The body is forgiving in the hand, dense in the fire, useful past the death of the potter. It does not aspire to porcelain's whiteness or earthenware's softness. It is the clay that asks to be put to work.

Channeled within the philosophy of Sōetsu Yanagi, *The Unknown Craftsman: A Japanese Insight into Beauty* (adapted by Bernard Leach; Kodansha International, 1972), Mingei principles of anonymous craft and the dignity of utilitarian wares.

PBR starter values

Principled BSDF defaults derived from the sphere matte finish. Reasonable seed for Blender, Substance, Keyshot, Rhino — tune per material.

# finish:      matte
albedo        #a08068
metallic      0.00
roughness     0.75
ior           1.45
transmission  0.00
clearcoat     0.00
sheen         0.00
anisotropic   0.00
copy as JSON 
{
  "albedo": "#a08068",
  "metallic": 0.0,
  "roughness": 0.75,
  "ior": 1.45,
  "transmission": 0.0,
  "clearcoat": 0.0,
  "sheen": 0.0,
  "anisotropic": 0.0
}
Blender 4.x Python 
# Blender 4.x — Principled BSDF
# Stoneware Clay · finish: matte
import bpy
mat = bpy.data.materials.new(name="mat_stoneware")
mat.use_nodes = True
bsdf = mat.node_tree.nodes["Principled BSDF"]
bsdf.inputs["Base Color"].default_value         = (0.3515, 0.2159, 0.1384, 1.0)
bsdf.inputs["Metallic"].default_value           = 0.000
bsdf.inputs["Roughness"].default_value          = 0.750
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
# Stoneware Clay · finish: matte
# Run from Window → Scripting Console
import lux
mat = lux.createMaterial(name="mat_stoneware", materialType="Generic")
mat.setProperty("diffuse",      (160, 128, 104))   # 8-bit sRGB
mat.setProperty("metallic",     0.000)
mat.setProperty("roughness",    0.750)
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": "Stoneware Clay \u00b7 finish: matte",
  "baseColor": {
    "r": 0.3515,
    "g": 0.2159,
    "b": 0.1384
  },
  "metallic": 0.0,
  "roughness": 0.75,
  "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_stoneware",
      "pbrMetallicRoughness": {
        "baseColorFactor": [
          0.3515,
          0.2159,
          0.1384,
          1.0
        ],
        "metallicFactor": 0.0,
        "roughnessFactor": 0.75
      },
      "extensions": {
        "KHR_materials_ior": {
          "ior": 1.45
        }
      }
    }
  ]
}
USD Preview Surface 
# USD Preview Surface — UsdShade.MaterialLook prim attributes
# Stoneware Clay · finish: matte
def Material "mat_stoneware" {
    token outputs:surface.connect = </mat_stoneware/PreviewSurface.outputs:surface>

    def Shader "PreviewSurface" {
        uniform token info:id = "UsdPreviewSurface"
        color3f inputs:diffuseColor = (0.3515, 0.2159, 0.1384)
        float   inputs:metallic     = 0.000
        float   inputs:roughness    = 0.750
        float   inputs:ior          = 1.450
        float   inputs:opacity      = 1.000
        float   inputs:clearcoat    = 0.000
        token   outputs:surface
    }
}
↓ download glTF material
ProcessWheel-Throwing (Ceramics)
Used inDinner Plate (Ceramic) · Ikebana Vase (Ceramic Vessel)
Substitutes
Porcelain

Citations