The sponge with which some people regularly soap themselves in the bath is really the skeleton of a particular type of natural sponge. Bath sponges are supported by a framework of a resilient, elastic material called ‘spongin’, and it is this that makes up the bathroom sponge.
Bath sponges are found in warm shallow seas, and in various part of the world ‘sponge farms’ were once established and bath sponges grown from cuttings for eventual sale. Few such farms still exist, but sponges are still grown commercially in the Greek Islands and in the Philippines. The increased use of synthetic sponges cheaper to produce, although not as hard wearing has meant that there is now little demand for natural sponges, except for cleaning and polishing in certain industries.