The conventional office paper recycling process reduces used paper to a pulp prior to cleaning and re-forming. The difficulty of collecting and sorting waste paper, the low process yield and the energy required to re-form the used paper make this process economically unattractive and potentially environmentally less preferable than virgin production. Together these have resulted in a low recycling level for European office papers. An attractive alternative is the possibility of recycling office paper within the office, without destroying the mechanical structure of the paper. This paper reviews 104 patents filed mainly since the mid 1990s that propose technologies to achieve this. The patents are grouped into three categories: de-colouring the toner or ink; obscuring existing print; print removal by adhesion, ablation, abrasion or chemical processes. Some of these processes require new substrates, coatings, inks or toners, and to date only one has been released commercially. The various technology options are compared, and an assessment is offered of their likely future development.