The swelling of fibres in water has a large impact on the consolidation of the web in papermaking and thus on the properties of the final paper. The water taken up by the fibre is held by many different mechanisms and it is not always clear from the techniques used which quantity of water is being measured. In this report, an attempt is made to obtain more knowledge regarding the water- holding mechanisms of fibres, by studying the amounts of bound water, of pore water and of the total water in the fibres. Effects of delignification, recycling, beating and ion exchange are examined. It is concluded that the amount of bound water is a reflection only of the wood polymer composition of the fibre, whereas the pore water is affected by physical changes of the fibre wall. The ionic charges mainly affect the surface water of the fibre.