This paper describes some recent work to improve the waterproofness of both heavy and light leathers. Several tests are needed to characterise the waterproofness of a leather, and those in common use are described. There are two ways to improve the waterprofness of a leather: the resistance to water can be increased by filling the capillary spaces, or the fibre surfaces may be treated to make them highly water-repellent. Recent work to find a surface treatment for vegetable tanned sole leathers has met with only limited success, and filling treatments remain the best way of waterproofing such leathers. On the other hand, the fibre surfaces of full chrome upper leathers can be successfully treated to improve greatly the resitance of the leather to water but it is disappointing to find that as much as 10per thousand of agent on the leather weight is usuallly needed for effectiveness. Further work to develop a treatment that is both effective and cheap is necessary. Two methods which appear promising involve 1) the application of two separate waterprofing treatments or 2) the dilution of a powerful agent with a relatively cheap and moderately effective agent.