Conversation so far:
Who did the artwork for Dr. Seuss books?
Theodor Seuss Geisel is known for his work writing and illustrating more than 60 books under the pen name Doctor Seuss.
What did Theodor Seuss Geisel draw?
Geisel evidently enjoyed drawing architecturally elaborate objects.
What books did Theodor Seuss Geisel illustrate?
The Cat in the Hat is a children's book written and illustrated by Theodor Geisel
Did Theodor Seuss Geisel draw anything besides machines?
Geisel's style was unique – his figures are often rounded and somewhat droopy. This is true, for instance, of the faces of The grinch and the Cat in the Hat.

Question: lines that accompany what?
Self-contained rewrite: Theodor Seuss Geisel drew lines that accompanied what?