Copied and edited into steps, by Denny B., from another posting, by ICM.
Ok, 1st in my tutorial about slabs--in fact on the picture at the top, I gave the sequence for knapping a slab. Let's review.
Start either, at the tip, or base--it does not matter, but pick one, and stick with it.
Ok, lets say you picked the base--I did ..
Now, knap from the base to the tip. STOP!
Turn it over and knap from the base to the tip STOP!
Now, you have two opposite quarters knapped from base to tip.
NOW, swap ends and put the tip up. Knap from the tip to the base. STOP!
Turn it over, and do the other side, tip to base.
NOW, you have knapped all 4 quarters; and you have covered the whole slab.
The problem with doing it all on one side, is any flake that goofs up, or is short creates, a problem; and then you are flaking on to a flat surface, which has a problem straight across from it.
Also, you must make sure your platform is below center line, and is well ground.
OK now, when you hold the slab in your hand, against the pad; set the angle, so you are ALWAYS knapping towards your thumb. That is your angle; stick with it; always aim for the thumb, and you will develop a set angle.
hope this helps ...
If God did Not want us to eat animals why did he make them out of meat?"Adapt, Improvise, Overcome!"