After I made my first whip and second whip out of paracord to learn the plaiting skills, I made my third whip out of cow leather from Tandy. I used an Australian Strander to cut the lace and a lace beveller to prepare the laces.
Here's my Australian Strander and homemade beveller. They are sitting on what's left of a piece of leather I got from Tandy, after cutting lace by going around and around. This is my 'learning' whip using leather. I definitively learned how not to cut laces.
For my first leather whip, I made the the core by soaking some laces in water, twisting them together and stretching them.
Start plaiting
Attach the core to the handle and continue plaiting
Finished with first layer
Cut laces for second layer
Second layer finished
Close-up of the handle showing the 5x8 Turks head knots. The heel knot was made with laces cut a little bit thinner.
I purchased some really thick leather and cut out an 18 inch fall. I beveled all edges, soaped it up good, and attached it to the plaited whip. For a 4.5 ft bullwhip, it cracks OK.