"Sweeping lines" refers to long and graceful curves or contours that are smooth and flowing.
Sentences with «sweeping lines»
With the slightest flight of the wrist he could project great sweeping lines of paint and textured fields of colour. (galleriesnow.net)
With sweeping lines, a heart speaks to expansive emotion in a design dedicated to love. (novica.com)
More than once I found myself tracing with my eyes the gently sweeping lines from the windshield to the front of the hood. (articles.orlandosentinel.com)