One of the most effective ways to prolong the usage time of canvas bags is preserving them. Personally, I haven’t tried out the method yet but Rachel of 'Transient Expressions' after sewing her bag waxed it with a homemade mixture of household products. After waxing the bag gets stiffer and waterproof. The beeswax and paraffin are ideal preservatives which are sure to give your bag endurance and longevity.
I only wonder how long this method keeps the treated surface waterproof. If you've experimented with waterproofing your bags, you can share your opinions below!
Check out the tutorial on Transient Expressions.