Midjourney allows you to generate seamless repeating patterns that you can use to create fascinating designs. This is done using the Tile parameter denoted by –tile, which generates the tile you request that is designed in a way that produces a seamless design when repeated.
Midjourney's –tile Parameter Guide – AI-generated seamless tiles/patterns
This parameter can be useful when creating wallpaper, fabric, or texture designs. When you use the –tile parameter, Midjourney will create a single tile based on your prompt. This means that the initial image grid will consist of 4 different 1-tile designs that Midjourney has generated based on the input text.
To see how this tile looks when repeated, Midjourney suggests using this Seamless Pattern Checker . Here you can process the generated tile image and see how it looks when placed side by side repeatedly.
Although Midjourney generates a seamless design for a tile without any defects, you may not like them all when you recreate them with multiple tiles. So you should use the pattern checker on a generated tile to check and see how the tile will look when repeated before adding it to your design or product.