Materials 101

Click through for original res and save. The image shows the process of making any VRay material. Follow the annotations. The 3rd window of the image is number referenced to the list below, it gives a short description of the important settings in the material editor.

1. Checkerboard. Turn this on to see the effect of reflections and refractions. Helps make more accurate materials.
2. Material name goes here. For your sake, remember to name them.
3. Diffuse slot. This can be a colour or an image for materials that have specific surfacing like timber. Keep any under 1000px to save RAM if you're working on a device with 8GB or less.
4. Reflection. Black to white scale. Pure black is no reflection, pure white is 100% reflective. Gray values give you varying levels of reflection.
5. Reflection glossiness. Governs sharpness of the reflections. 1.0 is the sharpest, think mirror. Lower values will blur reflections, like stainless steel. Do not set below 0.6.
6. Fresnel reflection. Keep on for all materials except mirror. Fresnel IOR value changes with material type. Default is 1.6, surface treatments such as varnished timber and polished concrete go up to 4.0, metals are 25.
7. Refraction. Governs refraction of materials. Black to white scale. Pure white is complete refraction, like glass. Leave this on pure black for opaque materials.
8. Refraction glossiness. Used only for glass/acrylic, works on the same black to white scale principle as reflection glossiness. Set to 1.0 for clear glass, incrementally down to a maximum of 0.7 for a frosted effect. Will increase render times.
9. IOR. Index of Refraction. Defines how much a material refracts incoming light rays. 1.0 is air, 1.333 is water, 1.6 is glass. Google "refractive index" for a comprehensive list.
10. Affect shadows. Turn this on for more realistic glass and other refractive/transparent materials. Leave off for opaque materials.
11. BRDF model. Change to Microfacet GTR (GGX) to ensure your materials look their best.