ForMatter/Materials/paint/Gouache (Designers / Opaque Watercolor)
mat_gouache_designers

Gouache (Designers / Opaque Watercolor)

water-soluble pigment + binder + opacifier coating, opaque rather than transparent · gouache, designers gouache, opaque watercolor, poster paint, Holbein Acryla Gouache (acrylic-binder variant)

Watercolor's opaque cousin — same water-thinned binder (gum arabic), same pigments, but with added chalk or barium sulfate opacifier so the paint covers what's beneath it rather than letting the paper show through. The illustration paint of every mid-century commercial illustrator (Push Pin Studios, Saul Bass, the Polish poster school), every architectural rendering (the watercolor-architectural-rendering canon), every flat-color graphic-design comp before computers. The matte, flat-color hand that dries with no surface sheen and reads as a painted illustration. The 'designers gouache' designation distinguishes the high-pigment-load illustration grade from the cheaper 'school' or 'poster' gouache. Holbein, Winsor & Newton, and Schmincke are the heritage canon; Daniel Smith and Holbein Acryla Gouache (acrylic-binder variant — water-thinable but waterproof when dry) are the modern variations. Buy from Dick Blick / specialty art-supply houses.

Water-soluble pigmented coating, similar formulation to watercolor (pigment + gum arabic binder + glycerin humectant + water) but with added opacifier — typically 10-20 percent barium sulfate (precipitated chalk) or chinese white (zinc oxide) — that scatters light and prevents the paper showing through. Pigment-to-binder ratio higher than watercolor (more pigment loading). Tube format standard (15-30 ml typical). Acryla Gouache and similar modern variants substitute acrylic emulsion for gum arabic binder, retaining water-thinning and water cleanup but producing a waterproof film when dry (the canonical fault of traditional gouache — water-re-activates the dry film — is solved by acrylic-binder versions). Lightfastness ratings same scale as watercolor. Dries to flat matte film with no surface sheen, even film thickness — the property exploited for graphic-design / illustration flat-color work. Brushes evenly without ridges; can be re-coated for exact-color match work; can be airbrushed (with thinning) for smooth gradient work. Cleans up with water (traditional gum arabic) or water-then-soap (acrylic Acryla variant). Resin identification: not part of consumer recycling; tube packaging mixed-material.

mechanical

  • bindergum arabic (traditional) or acrylic emulsion (Acryla Gouache)
  • opacifierbarium sulfate or chinese white (zinc oxide), 10-20 percent
  • lightfastness_blue_wool_scaleSeries I-V depending on pigment
source: Holbein Designers Gouache product chart; Holbein Acryla Gouache technical data; Winsor & Newton Designers Gouache color reference

Sustainability

  • embodied carbon kg co2e per kg6.0
  • sourceEditorial estimate from ICE / Granta CES EduPack class data for artist paints, cradle-to-gate. Lower than oil paint per-kg (no solvent), comparable to watercolor.
  • recyclabilitylow — tube packaging mixed-material; empty tubes not in standard recycling streams
  • biodegradablepartially for traditional gum arabic binder; not for acrylic-binder Acryla variants
  • certificationsASTM D5724 (gouache spec), ASTM D4236 (chronic health hazard labeling), REACH compliant
  • localityglobal production by Holbein (Japan), Winsor & Newton (UK), Schmincke (Germany), Sennelier (France), Royal Talens (Netherlands), Daniel Smith (US)
visual
matte flat-color finish with no surface sheen, even covering at moderate film thickness; the canonical illustration / graphic-design paint look
tactile
tube paint hand similar to watercolor wet, dry film slightly chalky vs. watercolor's harder cured surface
weight perception
tube format compact (15-30 ml typical); film essentially weightless
acoustic
near-silent in handling

PBR starter values

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

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

# finish:                   matte
albedo                      #a85838
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": "#a85838",
  "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
# Gouache (Designers / Opaque Watercolor) · finish: matte
import bpy
mat = bpy.data.materials.new(name="mat_gouache_designers")
mat.use_nodes = True
bsdf = mat.node_tree.nodes["Principled BSDF"]
bsdf.inputs["Base Color"].default_value         = (0.3916, 0.0976, 0.0395, 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
# Gouache (Designers / Opaque Watercolor) · finish: matte
# Run from Window → Scripting Console
import lux
mat = lux.createMaterial(name="mat_gouache_designers", materialType="Generic")
mat.setProperty("diffuse",      (168, 88, 56))   # 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": "Gouache (Designers / Opaque Watercolor) \u00b7 finish: matte",
  "baseColor": {
    "r": 0.3916,
    "g": 0.0976,
    "b": 0.0395
  },
  "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_gouache_designers",
      "pbrMetallicRoughness": {
        "baseColorFactor": [
          0.3916,
          0.0976,
          0.0395,
          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
# Gouache (Designers / Opaque Watercolor) · finish: matte
def Material "mat_gouache_designers" {
    token outputs:surface.connect = </mat_gouache_designers/PreviewSurface.outputs:surface>

    def Shader "PreviewSurface" {
        uniform token info:id = "UsdPreviewSurface"
        color3f inputs:diffuseColor = (0.3916, 0.0976, 0.0395)
        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

Second life

repairabilityvery high — gouache re-wets with water at any time; the design-illustration tradition exploits this for re-workability.
recyclabilitylow — same as acrylic.
disposal pathdried gouache general waste.
typical longevity200 years (typical)
failure modes
  • re-wet vulnerability (paintings can be damaged by water)
  • color-shift in non-archival grades
  • cracking in heavy-application areas

Winsor & Newton designers gouache technical bulletins; Schmincke gouache literature.

Further reading