Paper adhesion describes how well a colored pencil's core material sticks to the surface of the paper.
A pencil with good paper adhesion deposits color easily, even with light pressure.
Poor paper adhesion may result in weak, patchy, or inconsistent color deposits, requiring additional pressure or repeated strokes.
Paper adhesion is a combination of factors but in the Lab, we’re mostly concerned about the pencil's formulation.
Other contributing factors include the texture of the paper and any surface polishing or coatings on the paper, plus the pressure you apply.
Paper adhesion is different from layer adhesion, which describes how well a pencil deposits color over existing layers of colored pencil.