Notes on hatchet manufacture:
:32 - explains that you cannot only chip one side - the joke is that you have to thin both sides, otherwise you create a turtleback
1:01 - he does not recommend using a hammerstone that is neither too hard, nor too soft
4:12 - explains making a platform on the opposite side of a thick area, to remove the thick area
7:32 - He explains that the price of the hatchet would cost about 12 pesos, which is about .80 cents US. But, if it is more detailed, it would cost more. This piece is considered "rustic", but maybe a knife could be more expensive and have better detail
8:32 - If I detail this really good with a piece of deerhorn, the cost could double. I would need to use a piece of deerhorn or copper to remove smaller flakes