So what good is a log of alternating coloured wood? How do you use it?

Like this.

First the log needs to have 1mm thick slices cut off of the end. Exacting work and risky. I set the blade so that it does not cut all of the way through, leaving a small amount of wood intact to keep the slice that I want on the log, preventing it from getting destroyed.

Looks like this.

Then, using a Japanese style saw, and using the slice itself as a guide, I cut through the remaining bit of wood.

Leaving me with a 1mm thick slice of striped wood.