Make sure the image file’s color space is set to Non-Color Data. It should be plugged into the Roughness input of the Principled BSDF. The Roughness map defines how rough a surface is. Make sure the image file’s color space is set to Color. It should be plugged into the Base Color input of the Principled BSDF. The Base Color map defines the color of a surface. Apart from the Displacement section, this setup works for both Cycles and Eevee. Usage of most materials using the Principled Shader.
