How to Make a Custom Painting from the Three Themed Paintings

Prerequisites

Before you can craft a Custom Painting, you must already have one Overworld Painting, one Nether Painting, and one End Painting in your inventory. These three are the only inputs for the Custom Painting recipe. If you are missing any of them, craft the missing themed painting first using its own shaped recipe.

The Combining Recipe

Open a crafting table with all three themed paintings on hand. The Custom Painting is produced by a shaped crafting recipe that uses the Overworld Painting, Nether Painting, and End Painting together. Arrange them in the grid exactly as the recipe shows. A shaped recipe requires the correct positions, so do not scatter them randomly.

Collecting the Result

Once the grid matches the recipe, the result slot displays the Custom Painting. Move it into your inventory. The three themed paintings are consumed in the process, so you will need a fresh set for every additional Custom Painting you want to make.

Repeat Crafting

To make more than one Custom Painting, repeat the entire chain: craft an Overworld Painting, a Nether Painting, and an End Painting, then combine them. Setting up a dedicated crafting area with the themed paintings pre-crafted speeds this up considerably.