Those working in V-Ray versions lower than 3.1 should be careful, as the materials in the BRDF section use Microfaset GTR (GGX). If your version is older than 3.1, the BRDF field will be empty. Choose Blinn, Phong, or Ward – whichever you prefer.

For Corona render, it is recommended to use a version no lower than 1.5, as the glossiness of materials is set with PBR in mind.