Background 
There are two types of backgrounds:
Advancement Background 
This background works like vanilla advancement background. The texture should be 16x16 and it is tiled across the whole space:
Example 
json
{
	...
    "background": "minecraft:textures/gui/advancements/backgrounds/adventure.png"
	...
}Custom Background 
Properties 
Texture 
Property texture defines the texture that will be used as background.
Width and Height 
Properties width and height define respectively width and height of the texture.
Position 
Property position defines how the texture will be positioned on the screen. Possible options are:
- tile- Texture is tiled and repeated across the whole screen.
- fill- Textures is scaled such that it covers the whole screen.
- fill_width- Textures is scaled such that it covers the width of screen.
- fill_height- Textures is scaled such that it covers the height of screen.
If not set defaults the texture is centered on the screen and has original size.
Example 
json
{
	...
    "background": {
    	"texture": "minecraft:textures/gui/title/background/panorama_0.png",
		"width": 1024,
		"height": 1024,
		"position": "fill"
	}
	...
}JSON Structure 
| Property | Type | Required | 
|---|---|---|
| texture | string | yes | 
| width | integer | yes | 
| height | integer | yes | 
| position | tileorfillorfill_widthorfill_height | no |