Intermediate filaments (protein)

• Intermediate filaments are so called on account of their diameter (10 nanometers) which is intermediate between microfilaments (6 nanometers) and microtubules (25 nanometers)
• Although microtubules are the same in every cell, and intermediate filaments (lamins) in the nucleus are standard, cytoplasmic (cell “empty” space) intermediate filaments  are specialized according to their tissue type and embryonic origin.
• Concerning the skin: Keratins are the intermediate filaments (polymers of keratin monomers) which determine the shapes (and strength) of epidermal skin cells once they reach the surface (keratinocytes).

Reference: The Cell: A Very Short Introduction. Allen T. Oxford University Press