The plant cell wall is an intricate assembly of biopolymers that is often proportionally dominated by cellulose, which is particularly true of secondary cell walls. Lignin also forms a major constituent, imparting strength to tracheary elements and fibres. Lignin has been described as being largely derived from three cinnamyl alcohol derivatives, p-coumaryl, coniferyl, and sinapyl alcohols, that differ only in the degree of methoxylation on the aromatic ring. The mechanism of export of monolignols from their site of synthesis to the cell wall continues to be questioned, while assembly in the apoplast is known to proceed by random coupling following monolignol oxidation by laccases and/or peroxidases. In recent year, the classical dogma describing lignin chemistry and composition has been shown to be an oversimplification, as several native lignins have revealed the incorporation of a wide array of non-traditional monolignols. For example, a number of plants inherently possess ester-linked pendant groups, including, ferulates, p-coumarates, p-hydroxybenzoates, and acetates, that exist exclusively at the γ-positions of lignin sidechains. More specifically, in the case of grasses, coniferyl and sinapyl p-coumarate are synthesized and exported to the apoplast, while in poplar and willow, but not eucalyptus, p-hydroxybenzoates decorate the lignin. Biologically, these observations clearly illustrate the inherent plasticity of lignification, while from a biotechnological perspective provide the impetus for the formal ‘design’ of lignins. We have systematically discovered several of genes responsible for decorating the lignins, and have functionally validated them in planta, ultimately producing lignins with unique chemistries and structure.