sketchbook
n. countable B1 Intermediate US //ˈskɛtʃˌbʊk// UK //skˈɛtʃbʊk// sketch·book
n. a book of blank pages for drawing or writing notes. You use it to keep your quick drawings and ideas in one place.
n. a book of blank pages intended for drawing, writing, or recording notes. Often used by artists or writers to capture spontaneous ideas or observations.
She carries a small sketchbook with her to draw people in the park.
The architect filled his leather-bound sketchbook with rough plans and elevation drawings during the site visit.
While digital tablets offer convenience, many illustrators still prefer the tactile experience of a physical sketchbook for their initial concept development and rapid ideation.
From sketch + book.