AbstractTraditional methods of studying natural folds are reviewed. A new method of describing cleavage attitude in folds is presented; the β plot. The combined graph of dip isogon angle ϕ (Hudleston 1973) and cleavage angle β is proposed as a linked classification of fold and cleavage geometry. Plots of β and βϕ are given for three natural fold examples. The classification is extended to the geometry and strain attitude (βϕ5) of two finite‐element models and the classical folding models. Results are compared and some tentative conclusions drawn on the relationship of cleavage, theXYplane of strain and di