How to get UI elements on card not to shine through?

I’m making a mini game where you are supposed to figure out card patterns.
I’m using two quads with opposite facing normals for the front and back surfaces of the cards, and then UI text objects for the values and suits of the cards. They are all parented to a world canvas and are using an ortographic camera.

Hierarchy of the card:
CardPrefab (Empty)

The UI text is placed slightly in front of the card to prevent that it’s visible from the backside, however this does not seem to be working. Moving the cardback around in the internal hierarchy doesn’t do anything either. Whats the problem?

So I made a workaround where I used 3D Text Mesh-objects instead of UI Text. I suppose it works as good!