Why won't my mask work with Principled BSDF?

Hello guys! I decided to ask for help here after being unable to find solutions through google. I’m trying to make a wooden crate with some text on one face. This is what it looks like, with the diffuse, gloss, and normals materials correctly plugged to their respective slots.

I decided to try making a mask and to put an under texture for the text instead of editing the original diffuse. I attempted this with the help of Andrew Price’s jerry can rust tutorial from 2014. This was way before Principled BSDF was available but I thought applying the simple node set up would still work. This is how it looks.

It sort of works, but only when viewing the crate through “Materials” mode in the viewport. However, when switched to render it only appears grey.

This is what it looks like when rendered.

What am I doing wrong? :frowning:

You appear to be using a ‘Mix Shader’ node when it should be a ‘Mix Color’ node.

Oh, it works now! I can’t believe I overlooked that. Thank you very much, Nerk!