Mixing of the aqueous suspensions was carried out using an Eppendorf epMotion 5075 automated liquid handling station. The starting material suspensions were held on a specially constructed low-profile multiposition magnetic stirrer so that the solids did not settle out during dispensing. The current version of the stirrer has places for four suspensions held in glass vials. The stirrer uses rotating magnetic fields from three sets of stationary coils which are directed to the four stations via soft iron pole pieces. The design minimises the height of the bottom of the vials to increase the volume of material that can be processed, currently to 30 cm 3 per suspension. Stirring speed can be varied from 240 -960 rpm. The conventional PTFE bar stirrers originally used have been replaced with a custom designed 3D printed stirrer with embedded neodymium iron boron magnets. The design has a centre hole which allows the Eppendorf dispensing tips to aspirate from a lower level and reduces the dead volume of liquid which cannot be taken from the vial. The components were dispensed by volume into glass vials (one per formulation) and then the liquid handler mixed each formulation by repeated aspiration and dispensing. The dispensing parameters of the Eppendorf handler were adjusted to allow for the increased density and viscosity of the suspensions compared to water and optimisation of these parameters should allow closer match between nominal and measured compositions (Fig. ).