A high-speed, laboratory-scale, film-press coater was used to study the surface structure characteristics of aqueous-based pigment coatings when applied to a paper substrate. The film-press coating trials were monitored on-line with a high-resolution digital camera. The resulting images were quantified using a four-segmentation method, developed specifically to investigate the 'degree of dryness' experienced by the coating layer at different times from the initial application of coating. This method was based on an assessment of the grey level (CL) intensity described by the on-line images. Coating consolidation times were found to be quite rapid, with the first critical concentration (FCC) occurring at 0.020 s from application and the second critical concentration (SCC) occurring at 0.041 s. These results differ greatly from many consolidation studies in the literature, which typically report much longer consolidation times. This is primarily because they have used model substrates (usually non-porous), simplified coating formulations and often applied coat weights that are significantly higher than would commonly be used with film-press coating technology. This study has therefore highlighted the importance of developing laboratory equipment that accurately mimics film-press technology on porous substrates, and also the significant contributions of porous substrates and coating thickness (among others) on consolidation processes. It has subsequently shown that if these factors are removed from model systems, the influences on FCC and SCC are considerable. Other results were that higher nip pressures influenced the initial dewatering characteristics of the coating, but at longer times, the nip pressure had little effect on the resulting structure. Lower coat weights resulted in faster consolidation times as expected, and coating speed had little effect on the resultant images or coating structure. (C) 2008 Elsevier Ltd. All rights reserved.