What defines illustration board?

Illustration board is characterized by its thick cardboard composition, which provides a sturdy and durable surface for various artistic applications. It typically features either a smooth or textured surface, making it suitable for different mediums such as paint, ink, and pencil. This versatility allows artists to achieve detailed illustrations or mixed media works while ensuring that the surface can withstand handling and multiple layers of materials.

The other options describe materials that do not match the specific qualities of illustration board. For example, thinner paper used for sketches lacks the robustness and sturdiness required for finished artwork that illustration board provides. Additionally, while acid-free paper is an important feature for archival quality in some art practices, it does not specifically define illustration board. Likewise, while some types of paper may be better suited for detailed pencil work, illustration board’s characteristics extend beyond just pencil usage, making it a more versatile choice for illustrators and artists.