A line which defines the outermost limits of an object or shape, similar to the outline, and separates the positive space from the negative space is called .

Contour line

Explanation:

Contour line is defined as the line that is used for precisely defining the edges of any shape,thing or object .It marks the the boundary to define the details of sculpture or object. It is drawn to display expression or shape and action.

It is used for partitioning the outside area or space of sculpture known as negative space from the sculpture or object which is called positive space.

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