Preset
Several presets are available. You can also add your own presets which will appear in this list. For details, see: XXXXX
Scale
This parameter is very useful for quickly adapting the amount of transparency/translucency to the size of the object that the material is applied to. For example you might like the overall look when you use one of the preview scenes, but when you apply it to a very small object in your scene, it looks much too transparent and not solid enough. In this case, simply lower the Scale and the material will start looking more and more solid. On the reverse scale, if you apply it to a large object and it looks too opaque, raise the Scale parameter.
Scale parameter from left to right: Default of 8, 1, 20.
Refractive Index
The main refractive index of the material. The visual result is that higher values will make the material look more reflective (if the Roughness parameter is low enough to show sharper looking reflections). Common values are between 1.3-1.6. It's recommended not to raise this value above 1.6-1.8 or it will create a much too reflective translucent material which will not look realistic, while also darkening the look of the SSS because more light is simply reflected off the surface, instead of going into the object and scattering inside.
Refr. Index at 1.2 and 1.7
Color
The main color of the translucent material.
Hue Shift
In certain translucent materials, the main color hue can "shift" as the light scatters inside the object. The result is you see the main Color you have selected but also a slightly different hue which is offset from the main Color. You can choose the amount of offset in degrees from the hue of the main Color, with 120 degrees being the maximum setting. Usually, small hue shifts are the most realistic, for example if you have a red candy material with a hue shift of around 30 will make the red also have hints of yellow in it.
Here the hue shift was set to 80 degrees for an exaggerated effect, which internally makes the main red color shift towards green. The resulting scattering effect now is red mixed heavily with green.
Invert Hue
Turning this parameter on can be useful for materials that actually show complementary colors in their scattering, such as milk, which looks mostly yellow but also shows tints of blue nearer to the light source. Checking this parameter will cause the tints to be the opposite hue in the color wheel, compared to your chosen Color setting.
Vibrance
This is the actual saturation of the virtual particles inside the value that scatter the light. Higher values will make the material look much more saturated and vibrant.
Using a bright red as the main Color, the Vibrance setting was changed: 0, 15, 50, 100
Density