Fig 6. Presentation of the three experiments.

(A) Material used for experiment 1, the animal skin used and the cylinder of the polishing drum. (B) Material used for experiment 2, the ochred and greased animal skin. Illustration of the chaîne opératoire reproducing an ochre tanning: obtaining the ochre powder and applying the ochre/grease paste on the hide. (C) Equipment used for experiment 3, the soil polish. A mechanical polisher covered with silt collected on the Landry site. Presentation of the manual (bottom left) then mechanical (bottom right) method of gravel gripping.