A 2"x4"x8' piece of lumber cand be "ripped" on a table saw into several thin 8' strips. Alternatively, the wood and be crosscut or choppped in the several 2"x4" blocks.

Tusks used to make antique ivory chips were crosscut. All of the modern repros being produced were cut lengthwise or "ripped" in order to make as many blanks as possible.

I have 750 ivory chips on my website. Every one was made from ivory tusks that were crosscut.