Inherently rotational molding produces uniform wall thickness in the same manner in which thermoformed or blow molded parts are. Single surface processes such as rotomoulding and blow molding do not have as good a wall thickness tolerance as two surface processes such as extrusion.
The usual wall thickness tolerance for a large part would be in the range of +/- 15-20% whereas with a more precise smaller part, the tolerance range is +/- 10-15%. This wide tolerance range in rotational molding, blow molding and thermoforming results in a standard for which minimum wall thickness is provided rather than nominal wall thickness.