We present new photometric data from our Herschel guaranteed time key programme, the Dwarf Galaxy Survey (DGS), dedicated to the observation of the gas and dust in low-metallicity environments. A total of 48 dwarf galaxies were observed with the PACS and SPIRE instruments onboard the Herschel Space Observatory at 70, 100, 160, 250, 350, and 500 mu m. The goal of this paper is to provide reliable far-infrared (FIR) photometry for the DGS sample and to analyse the FIR/submillimetre (submm) behaviour of the DGS galaxies. We focus on a systematic comparison of the derived FIR properties with more metal-rich galaxies and investigate the detection of a potential submm excess. The data reduction method is adapted for each galaxy in order to derive the most reliable photometry from the final maps. To study the variation in the dust properties with metallicity, we also include galaxies from the Herschel KINGFISH sample, which contains more metalrich environments, totalling 109 galaxies.