English: Sphere eversion (turning inside out) keeping hexagonal symmetry, the halfway stage (Morin surface, both sides equally privileged), flattened with folds along a regular hexagon, cut out of doubly colored paper (red/green). Eversion is impossible using full rotational symmetry but any 2n-gonal suffices. The depicted part is homeomorphic to a cylinder/collar/bottleneck, to be glued to two spheres opposite oriented. Note the sextuple intersection in the center, double intersections between different colors and fold annihilation at the vertices.

English: Sphere eversion (turning inside out) keeping hexagonal symmetry, the halfway stage (Morin surface, both sides equally privileged), flattened with folds along a regular hexagon, cut out of doubly colored paper (red/green). Eversion is impossible using full rotational symmetry but any 2n-gonal suffices. The depicted part is homeomorphic to a cylinder/collar/bottleneck, to be glued to two spheres opposite oriented. Note the sextuple intersection in the center, double intersections between different colors and fold annihilation at the vertices.