Line quality refers to the visual characteristics of a line, such as its thickness, texture, and direction.

Scumbling is not a common mark-making technique, while stippling, cross-hatching, and hatching are all widely used.

Hatching is a mark-making technique that involves creating a series of short, parallel lines.

Vincent van Gogh is known for his use of bold, expressive lines, which can be seen in works such as "The Starry Night".

Stippling is a mark-making technique that involves using dots to create a sense of texture or shading.

Leonardo da Vinci is known for his use of delicate, precise lines, which can be seen in works such as the "Mona Lisa".

Cross-hatching is a mark-making technique that involves creating a series of intersecting lines.

Jackson Pollock is known for his use of gestural, fluid lines, which can be seen in works such as "Blue Poles".

Scumbling is a mark-making technique that involves using a variety of mark-making techniques to create a sense of texture or shading.

Piet Mondrian is known for his use of bold, graphic lines, which can be seen in works such as "Composition with Red, Blue, and Yellow".

A contour line is a single, continuous line used to create a drawing or image.

Vincent van Gogh is known for his use of gestural, expressive lines, which can be seen in works such as "The Starry Night".

Scumbling is a mark-making technique that involves using a series of short, curved lines to create a sense of texture or shading.

Leonardo da Vinci is known for his use of delicate, precise lines, which can be seen in works such as the "Mona Lisa".

A contour line is a single, continuous line used to create a drawing or image.