The shoes seem to work and those have to do quite heavy work while using. To get the jellyfish leather for shoes strong, Charlotte applied many layers of jellyfish leather on top of each other. This also then gives the interesting looks. BTW, collagen when applying the process of making leather, ie taking all the other stuff that sits in the skin of an animal, and apply stuff to make the binding of the collagen stronger, results in very string material. Collagen has the properties that by nature it already creates string connections amongst the molecules. In addition it is very durable, think of your own skin how durable it is, and how flexible and all. Collagen from jellyfish is not different. The challenges are more in how to collect the dead jellyfish, and how to transport it to the location where it'll be further processed, as well as to make the leather making process as efficient as possible to be able to compete with the prices of the leather coming from cattle.