Custom Materials are able to be made through the DevUI, this can be accessed by pressing CTRL + Left Shift + T, this menu allows you to create, import, and export custom Materials for later use.

Any Material exported with this tool will be placed on your Desktop with it's assigned name as a .json file. These .json files are able to be added to an AssetBundle, which will automatically be loaded and registered by KitchenLib.

The CustomMaterials class has methods to assist you if you want to manually load materials from a .json file:

Material GetCustomMaterial(string materialName) // Used to get a custom Material which has been loaded ( Same as MaterialUtils )
Material LoadMaterialFromJson(string json) // Used to load a Material directly from JSON content. ( string json - is the .json file content, not the file itself )