Noun
English Wikipedia has an article on:Bristol boardWikipedia
Bristol board (countable and uncountable, plural Bristol boards)
A heavyweight paper used for technical drawing, illustration, and other two-dimensional art forms.
Synonym: Bristol paper
Bristol board and even heavier acid-free boards, frequently with smooth finishes, are used for drawing fine detail and do not distort when wet media (ink, washes) are applied. Source: Internet
Its large size allows me to transfer images onto the Bristol board which I use for most all of my artwork. Source: Internet