Horizon line: The horizon line is a real line that can be seen in nature, where the sky meets the land or water. In art, the horizon line is often used to create a sense of depth and space. For example, in the painting "The Great Wave Off Kanagawa" by Hokusai, the horizon line is used to create a sense of vastness and emptiness.
Tree line: The tree line is the point at which trees can no longer grow due to the harsh conditions of high altitude or cold temperatures. In art, the tree line can be used to create a sense of isolation and desolation. For example, in the painting "The Wanderer Above the Sea of Fog" by Caspar David Friedrich, the tree line is used to create a sense of loneliness and insignificance.
River line: The river line is the path that a river takes as it flows through the land. In art, the river line can be used to create a sense of movement and flow. For example, in the painting "The Seine at Argenteuil" by Claude Monet, the river line is used to create a sense of tranquility and serenity.
Coastline: The coastline is the boundary between the land and the sea. In art, the coastline can be used to create a sense of contrast and division. For example, in the painting "The Cliff Walk at Pourville" by Gustave Courbet, the coastline is used to create a sense of drama and conflict.
Cloud line: The cloud line is the point at which clouds appear to meet the sky. In art, the cloud line can be used to create a sense of mystery and uncertainty. For example, in the painting "The Storm" by Théodore Rousseau, the cloud line is used to create a sense of foreboding and threat.
Mountain line: The mountain line is the outline of a mountain range. In art, the mountain line can be used to create a sense of grandeur and majesty. For example, in the painting "The Third of May" by Francisco Goya, the mountain line is used to create a sense of power and dominance.
These are just a few examples of natural line in art. There are many other ways in which artists can use natural lines to create expressive and evocative works of art.