The Black Diamond Door (Sn0wy Lore)

Overview
The Black Diamond Door is one of the many series of doors that serves as a portal between the second dimension (2D world) and the third dimension (3D world; aka Earth).

Characters within the 3D world use a portal like the Black Diamond Door to travel between the 3D world and to the 2D world that they created within the Imagisphere'''. However, characters within the 2D world can use this door to travel to other 2D worlds''' because it is in the same dimension.

Use in videos
The main Sn0wCast use the door to travel to and from other 2D worlds. However, when Tw1g traveled to the Little Big Planet world for a new head, she ended up converting into a third dimensional character. It is now speculated that she has the ability to travel to and from the 2D world and the 3D world, but is unaware of this.

Wallace, on a regular bases, uses the door to travel to and from the 3D world to the 2D world: specifically the world he created within the Imagisphere: the Sn0wy World. Wallace is a third dimensional character using that alias to hide the fact that he is Evan.

Versions
There is one version of the door used by the Sn0wCast and it is the door with a black diamond on the top center of the door frame.

However, this is just one of the many different version of doors that serve the purpose of portals around the Imagisphere.

What is unknown is how one person within the 3D world creates a portal in the first place and how two world in the 2D world mutually connect.