Wiktionary
plain lines
n. (plain line English) vb. (en-third-person singularplain line)
Usage examples of "plain lines".
It was a time of precise and unimpelled delight, plain lines of blue and gray, things taken in, men returning, all scattered creatures come together from their day of tumbling in the sun.
The Nazca Plain lines and Easter Island heads, while more recent, might have made the list.