Material is stripping black from it, and adding unwanted transparency

I’m using a PNG sprite sheet to make a flipbook material.

There are two issues I’m experiencing:
A - There should be a black trim around the sprites, it’s being stripped from the material.
B - The material should only be transparent where it is in the PNG file, but it’s making the entire material semi-transparent.

Materials are a bit frustrating to me as I don’t quite understand them – so I can only assume I’m doing something wrong. I’ve attached some photos which should help clarify.

Preview of what’s happening
Sprite sheet (background is transparent)

It’s because you’re using additive blend mode, black is a value of 0 so it adds nothing.

Of course … thank you that helped a lot.

I changed blend mode to masked and plugged the Alpha return from the Flipbook node into opacity. Everything is fixed.