When you select Create Modifier, a cube or sphere shape locator appears, which you can transform. Use the attributes in the lineModifier node to control the appearance of the toon lines within the realm of the locator. This is useful for locally editing line width, transparency, color, and other attributes. This affects all Paint Effects entities. The same modifier can be assigned to multiple nodes, for example, it could affect both Paint Effects strokes and toon lines at the same time. You can also have multiple modifiers assigned to one object; the influences of the different modifiers blend together. You may want to group the modifier with the object so they move together. For more information, see Use a modifier to alter toon line and brush attributes.