Comment on 'Statistical mechanics of developable ribbons' by L. Giomi   and L. Mahadevan
  Giomi and Mahadevan [Phys. Rev. Lett. 104, 238104 (2010)] study the statistical mechanics of elastic ribbons and claim to provide evidence for "an underlying helical structure" of ribbon-like polymers even in the absence of intrinsic curvature (or, in the authors' words, "of a preferential zero-temperature twist"). They find a persistence length that is over three times that of a wormlike chain having the same bending rigidity. We show that these results are an artefact of the authors' flawed formulation, which produces a helical bias, and that no support for the described effect can be claimed. 
E. L. Starostin, G. H. M. van der Heijden
cond-mat.soft cond-mat.stat-mech