How do I setup a Decal for posters on a wall?

Alright…

Placing a 2d texture onto a 3d mesh that’s made for posters. However, when I apply the texture to the mesh, UE decides to fill in the extra space with a color. How do I get UE to ignore the blank space and only show the texture and make the rest of the mesh/texture transparent?

Example - poster of a triangle I want to put on a wall. When I make a material out of it and put the material on a cube, the outside of the triangle is bright white. How can I instead make that white area transparent?

Thanks! I have NO coding experience, so you might need to use some basic terms. :slight_smile: