IOR Values

Ior is a great way of adding more realism to gloss surfaces, by adjusting this in the shaders panel in Blender you can get that extra look of finish to your objects. A good lighting setup will help to bring things together. If you are using a gloss surface then you need to think carefully about the environment your object is situated in. Creating a skydome around your object can work well or if you are after a studio setup large area lights can function well.

IOR - The "index of refraction" controls the particular rate and degree that reflections increase with decreasing angle of incidence. The concept of IOR is commonly used to specify the parameter needed control the Fresnel effect in a realistic way. (The glossy "clear coat" layer on top of car paint actually *is* refractive, and the index of refraction controls the reflectivity as well.)

The IOR of water is 1.33.
The IOR of glass is typically around 1.54.
The default value of IOR in car paint is 1.45.

Decreasing the IOR will make the surface less shiny. Do not decrease it below 1. Increasing the IOR significantly past 2 will make the surface appear more metallic. Since the "clear coat" layer on car paint is not a metal, you shouldn't go much past 2 for realism. (In real life, certain extremely expensive paint jobs can get the IOR up to 2.)



haere are some more IOR values which I have taken from info from: http://blenderartists.org/forum/showthread.php/71202-Material-IOR-Value-reference

'Air': 1.000
'Bubble': 1.100
'Liquid methane': 1.150
'Ice(H2O)': 1.310
'Water': 1.333
'Clear Plastic': 1.400
'Glass': 1.440 - 1.900
'Light glass': 1.450
'Standart glass': 1.520
'Heavy glass': 1.650
'Obsidian': 1.480 - 1.510
'Onyx': 1.486 - 1.658
'Acrylic glass': 1.491
'Benzene': 1.501
'Crown glass': 1.510
'Jasper': 1.540
'Agate': 1.544 - 1.553
'Amethist': 1.544 - 1.553
'Salt': 1.544
'Amber': 1.550
'Quartz': 1.550
'Sugar': 1.560
'Emerald': 1.576 - 1.582
'Flint glass': 1.613
'Topaz': 1.620 - 1.627
'Jade': 1.660 - 1.680
'Saphire': 1.760
'Ruby': 1.760 - 2.419
'Cristal': 1.870
'Diamond': 2.417 - 2.541