In rolled impression, the movement depends on the tool’s cylinder shape and is generally consistent.
The “rolled” motif varies only according to the tool type. Understanding the structure of “rolled” motifs is therefore subject to understanding the structure of the roulette. For this reason we decided to create a roulette reference system that would include modern roulettes collected in the context of ethnographic searches and re-created roulettes.

Roulettes can be classified in several categories according to how they were obtained and/or to their manufacturing process and to the type of material used.
Our suggested roulette classification is based on the initial distinction between objects that are specifically constructed to be used as roulettes, and objects (found in natural settings or manufactured) that are reused as roulettes.

"Manufactured" roulettes include plaited roulettes and modelled roulettes. The former are built out of a single material (cord or flat fibre) or a composite material (simple or multiple tool and cord) which changes according to the particular ropemaking or wickerwork techniques. The latter are most frequently engraved wood cylinders.
Other objects used as roulettes may be natural objects (cereal ear, fish vertebrae, etc.) slightly altered into the shape of a cylinder, or cylinder-shaped artifacts (springs) reused as roulettes.