The use of standardized weights was designed to ensure consistency and prevent corruption but this did not always work out in practice. Legal records reveal that certain tax collectors used heavier weights than those prescribed, and that shop vendors reduced their weight. In both cases profits would have been illegally increased. The earliest weights were struck like coins and usually featured the image of the reigning emperor- the majority of these seem to have been produced in Constantinople itself. By the sixth century there was a much wider variety in design and production centres had sprung up across the provinces.