Abstract: The application provides a method of treating fibrous textile goods comprising treating the fibrous textile goods with an enzyme. This enzyme can be used to covalently link one or more active functional compounds to the fibres and/or to trap one or more acitve functional compound within an inter-fibre matrix and/or within an intra-fibre matrix formed by the action of the enzyme. Preferably, the enzyme is a traglutaminase, especially a calcium-dependent transglutaminase. The enzyme may be used to add primary-amine containing active agents to the textile goods and also for the addition of proteins or peptides that have functional groups linked to them.