This paper summarizes chemical technologies aimed at making bulking fibres, a technology mainly practiced in the area of tissue and hygiene products but also highly relevant for board products made by sheet stratification containing bulking layers in the middle of the board in order to improve the bending stiffness of the board. There is a long history of different ways to make bulking fibres albeit the fact that such technologies have scarcely been used for commercial stratified board (apart from a variety of different pulp types), but more in tissue and hygiene products. The objective is to review the very different approaches that may be used for the purpose of making bulking fibres.