Blender Metallic Black Material using Principled BSDF Shader - cgian.com
Principled BSDF – Blender Knowledgebase
texturing - Glossy BSDF on Image Texture with transparency - Blender Stack Exchange
Here's a free Principled BSDF Shader guide to help Blender users, an extract from the free PDF guide and YouTube tutorial below, hope you find it useful :D : r/learnblender