To symbolise the clothes of the early stonemasons, who wore leather aprons to protect themselves whilst at their work. This is just one of many legacies of the Operatives, continued by present day Freemasons. If you read the answer to this question in conjunction with the answers to two other questions frequently posed, namely ‘why is it necessary to adopt strange rituals?’ and ‘why do grown men run around with their trouser legs rolled up?’, you will hopefully appreciate that Freemasonry contains much symbolism, which applies as much to the way we dress as the words we use.