I started with 2-3 oz cow leather from Tandy

I created a core by cutting 8 feet of the 4-5 oz leather lace.  I un-evenly halved it (3-feet to 5 feet), tapered both ends, soaked it in water, soaped it up, lashed the shorted end to the longer end and twisted it.  I then left it to dry.  Edwards describes this method of making a core in his whip biblical book "How to Make Whips", pg 15: Step 1: Making the Belly Method 2

Attach the core to the handle

I cut out some leather from which I could strand out the lace

Using my Australian Strander, I cut the leather out as lace

I also cut out a long strip from which I could create the bolster

Now I can cut the lace for plaiting

Start plaiting the first layer: 10 laces

Half done

First layer finished

Now for the second layer.  I wanted to use black and natural laces, so I needed some black lace.  I took my side of leather

and cut out a piece from which I could make black lace.

I stained it black

and started stranding it

I covered the first layer with a bolster, attached the lace, and started plaiting: 16 laces

Plaiting the handle. Critics will note that the pattern is curving.  That's caused by un-even lace width as well as un-even pulling by the whip constructor (user error).  I'm plaiting two-over, two-under.  I don't know if I like the results yet.

Finished the plaiting, add heel and transition knots, fall and cracker

Close up of the handle