HIPS is polystyrene toughened with polybutadiene rubber, a lightweight, easily painted plastic with moderate impact resistance, similar to ABS but less tough.
High-impact polystyrene (HIPS) is polystyrene blended with polybutadiene rubber, which makes it tougher than plain polystyrene.
It is similar to ABS in strength but less impact resistant. It sands and paints easily, is lighter than ABS, and dissolves in limonene, which is why it is also used as a support material.
HIPS is a good option for lightweight models, display pieces, and parts that will be painted.