I’d wouldn’t have liked to have been the poor bod working out the algorithm for the packaging of Domus’ new ‘Piano’ tile range, designed by French siblings Ronan and Erwan Bouroullec. The collection is made from coloured clays to which layers of glaze are added in different widths. Measuring 75 or 100mm by 300mm, the five base colours of white, grey, blue, green and pink are grouped by the lead colourway in each box to determine the overall effect generated on the wall or floor. The piecing together of the widths aside, how one proves the quality control of the colourways for consistency across batches sounds like one of those mathematical conundrums that will defy experts for centuries. A bit like proving that 1=2 or The Seven Bridges of Königsberg.