1. A computer-implemented method for variably rendering a passage of text, the method comprising: for each glyph of a plurality of glyphs of the passage of text: obtaining, by the computer, a glyph representation corresponding to a current glyph, said glyph representation comprising a set of two dimensional coordinates; and varying, by the computer, said set of two dimensional coordinates according to a geometric transformation to obtain a varied glyph representation, said geometric transformation having been determined from statistical measurements of at least one geometric property from an ensemble of representations of said current glyph; and generating, by the computer, renderable output data comprising each varied glyph representation, such that when the passage of text is rendered to an output device, a given rendered representation of a given glyph subtly differs from other rendered representations of said given glyph according to said at least one geometric property.