Hong Kong's tropical cyclone warning signals are eight black shapes on a white plate: an upright T, an inverted T, four triangle arrangements for the No. 8 quadrants, an hourglass and a cross. For more than a century they decided whether ships ran, schools opened and offices emptied.

This system takes the plate as its entire material. Pure white fields, flat black geometry, three bevel greys and a strict escalation ladder, with bilingual labels set heavy: Chinese in a Ming face, English in a grotesque.