That's the bottom line

Blue Line, Georgia O'Keeffe, 1919, From the collection of: Georgia O'Keeffe Museum
This piece uses organic lines to make up its composition. To me it reminds of open flame or candle being lit.
Three-line Calligraphy, Yishan Yining, Kamakura period, late 13th century-early 14th century, From the collection of: The Museum of Modern Art, Gunma
Oriental calligraphy, here we see lines being used in beautiful harmony to create a written language.
Blue Lines and Forms I, Yi, Hee Choung, 2008, From the collection of: Korean Art Museum Association
This piece is line to the max. Not only are the forms outlined but there is an organic line creating a visual pathway that guide the eyes in a "S" like pattern around the painting.
The Winter 1, Kang, Kyung Koo, 2011, From the collection of: Korean Art Museum Association
The Winter 1, the lines in this piece make up the forest. The curves in the trees give an eerie feeling to the whole composition
Untitled, Chung, Hyun, 1997, From the collection of: Korean Art Museum Association
The lines in the composition give us a humanoid form. I personally think that this is my favorite artwork in this gallery.
Portrait 5 - Pyoam Kang, Sehwang, Kang, Kyung Koo, 1998, From the collection of: Korean Art Museum Association
Very interesting portrait by Kyung Koo Kang. The variation in line thickness give the portrait more dept and value.
The Woods 2, Kang, Kyung Koo, 2000, From the collection of: Korean Art Museum Association
Even though the composition is grey and black. With the shapes and lines the piece gives us the earthly feel.
Christ Crucified between Two Thieves (The Three Crosses), Rembrandt Harmensz. van Rijn, Dutch (active Leiden and Amsterdam), 1606 - 1669, 1653-1655, From the collection of: Philadelphia Museum of Art
In this powerful work the lines are used to give us deep contrast in lights and darks giving off a more drama and emotion.
Composition T, 50-5, Hans Hartung, 1950, From the collection of: Galleria Civica di Arte Moderna e Contemporanea Torino
The lines in this piece in this give off a oriental and urban feel. The lines on the lower left give off a graffiti type look, while the lower right looks like oriental calligraphy.
Aggression III, Mikalojus Povilas Vilutis, 1979, From the collection of: Modern Art Center / Modernaus Meno Centras
The straight line in this piece looks as if its attacking the form, like a bullet traveling toward the form. The curved red lines coming from the lower half looks as if the form was bleeding.
Border, J. Grantil Company, 1928–1929, From the collection of: Cooper Hewitt, Smithsonian Design Museum
The overlapping lines in the piece give us a since of home. Looking as if the forms are coming from the wild and into to your home.
Mother and Daughter, Egon Schiele, 1913, From the collection of: Leopold Museum
The lines curved in the picture give the subjects form and value to making the subject look more believable.
London: The Thames from Somerset House Terrace towards the City, Canaletto, 1750 - 1751, From the collection of: Royal Collection Trust, UK
The perspective shown in this piece guides the eyes across the painting in a straight line.
Figures in possum skin cloaks, William Barak, 1898, From the collection of: National Gallery of Victoria
The lines in this piece give the form shape and pattern.
Geometric Knife Drawing 09-03-09, Cho, Byung Wang, 2009, From the collection of: Korean Art Museum Association
Untitled, Chung, Hyun, 2008, From the collection of: Korean Art Museum Association