Creating Man-made Materials in Cycles - Blender Cycles Materials and Textures - page 169

The RUST_BUMP output added to the stencil to separate the metal surface from the rusty surface
26. Add an RGB Curves node (press Shift + A and navigate to Color | RGB Curves), two
ColorRamp nodes (press Shift + A , navigate to Converter | ColorRamp, and label them
as ColorRamp4 and ColorRamp5 ), a Noise Texture node (press Shift + A , navigate
to Texture | Noise Texture, and label it as Noise Texture2 ), and a MixRGB node
(press Shift + A and navigate to Color | MixRGB).
27. In the RGB Curves node's interface, click on the diagonal line to add a control point. In
the X and Y slots at the bottom, set the values to 0.50000 and 0.26000 , respectively.
Click again to add a new control point, and set X to 0.51000 and Y to 0.75000 .
28. Connect the Color output of the RGB Curves node to the Fac input of the
ColorRamp5 node.
29. Go to the ColorRamp4 node. Select the black color stop and change the color values
of R to 0.991 , G to 0.591 , and B to 0.084 . Select the white color stop and change
the color values of R to 0.105 , G to 0.013 , and B to 0.010 .
30. Click four times on the + icon on the ColorRamp4 node interface to add four new
color stops. Select 4 as the index number and move it to the 0.889 position. Change
the color values of R to 0.930 , G to 0.456 , and B to 0.105 . For index 3, set Pos to
0.754 , R to 0.624 , G to 0.250 , and B to 0.053 . For index 2, set Pos to 0.521 , R
to 0.418 , G to 0.159 , and B to 0.068 . Finally, for index 1, set Pos to 0.286 , R to
0.246 , G to 0.098 , and B to 0.034 .