This report explains the processes to prepare a herbarium for digital imaging. It is divided into four main sections. The introduction summarizes the aim of mass digitisation and lists the reasons why several institutions started mass digitisation. The second chapter focuses on the preparation phase as it is a critical part of the process. Here the similarities and differences of herbarium collections are examined. Though each collection has its own peculiarities, the main topics of preparation are the same in every digitisation project. Preparation is a complex and often lengthy process. Past experience shows that details are important: assessing the exact number of specimens, addressing the issue of barcoding specimens, getting the appropriate means for transportation, down to the choice of boxes for example, accounting for possible pest infestation and dealing with unmounted specimens. The third chapter addresses the preparation of a herbarium collection for the imaging process itself. Emphasis is on weighing the merits of 1) in-house imaging by ones own staff, 2) in-house imaging by a contractor, and 3) outsourced imaging toacontractor. This section also details the elements of the workflow that are necessary to achieve mass digitisation. The last section presents five case studies of mass digitisation by renowned institutions: Meise Botanic Garden, Meise (BE), The Royal Botanic Gardens, Kew (GB), Digitarium (FI), Naturalis (NL), and the Musée National d'Histoire Naturelle, Paris (FR).