Which feature is characteristic of products made using rotational moulding?

Hollow plastic products are a defining feature of items created through rotational moulding. This manufacturing process involves heating a plastic material in a hollow mould while it is rotated along multiple axes. As the mould spins, the plastic particles uniformly coat the interior surface, gradually building up to form a hollow structure. This technique is especially suited for creating large, lightweight items with thin walls, allowing for efficient production of products such as storage tanks, playground equipment, and automotive parts.

The other options do not fit the characteristics of rotational moulding. Thick metal parts are typically produced using different methods like casting or forging. Wooden textures pertain to materials associated with woodworking or composite products, which are not formed through rotational moulding. Layered designs might suggest processes like 3D printing or laminating, neither of which align with the singular structure characteristic of rotational moulding.