Substrate Reference
OCS defines six substrate types, each modeling how a physical medium affects perceived color. The Coated (C) substrate serves as the reference against which all others are measured.
Substrate Types
Coated
Smooth coated paper stock. Colors appear most vivid and saturated. The standard reference substrate for OCS.
Lightness Offset
0
Chroma Scale
100%
Texture
smooth
Uncoated
Uncoated paper stock. Ink absorbs into fibers, reducing saturation and slightly darkening colors.
Lightness Offset
-3
Chroma Scale
82%
Texture
matte
Screen
Digital display (sRGB). Colors are emitted light rather than reflected, appearing brighter with wider gamut potential.
Lightness Offset
+2
Chroma Scale
105%
Texture
glossy
Textile
Woven fabric (cotton/polyester blend). Dye absorption varies with weave, reducing chroma significantly.
Lightness Offset
-2
Chroma Scale
72%
Texture
woven
Plastic
Injection-molded or extruded plastic. Pigment is mixed into material, producing consistent but slightly muted results.
Lightness Offset
+1
Chroma Scale
90%
Texture
satin
Film
Transparent or translucent film substrate. Backlit or overlay use. Colors shift toward higher lightness with slight chroma loss.
Lightness Offset
+5
Chroma Scale
88%
Texture
glossy
Color Shift Model
Each substrate modifies the reference (Coated) color using two parameters:
- Lightness Offset: Added to the L value. Positive values make colors appear lighter (e.g., backlit film), negative values darker (e.g., ink absorption on uncoated paper).
- Chroma Scale: Multiplied with the C value. Values below 1.0 reduce saturation (e.g., textile dye absorption). Values above 1.0 increase it (e.g., screen emission).
The hue angle (H) is preserved across substrates. In practice, physical media may introduce very slight hue shifts, but OCS models the primary lightness and chroma effects.
Choosing a Substrate
- Use C (Coated) as your default for highest fidelity color matching.
- Use S (Screen) when the final output is digital display.
- Use U (Uncoated) for natural, tactile print materials.
- Use T (Textile) when specifying colors for fabric production.
- Use P (Plastic) for product design and packaging.
- Use F (Film) for signage, lightboxes, and translucent applications.