My first large point - mahogany obsidian slab

[Stickhead]

This is my first successful point of this size.  Up until now, I’ve been getting experience on arrow-sized points.  As you can see, I didn’t quite get it thinned all the way to remove the original surfaces.  Any tips on how I could have done this?  This was all pressure flaking, as I’ve had nothing but breaks result from percussion on slabs.  Any criticism or advice is welcome!
...Tom

[Outbackbob48]

Stickhead, lower your edge and make a nice strong platform and make another pass on each edge, big Ishi stick and pop your flakes at least to center or more, your point is going to be narrower but you can remove the polished saw marks. Turn it over and do the samething on the opposite side.  Bob

[1442]

Are you zig zagging the edges or working them square?
It's been a while since I've worked an obsidian slab but I think I remember preferring to zig zag obsidian slabs due to the obsidian being too slippery to seat my flaker on the square edge which caused a lot of flakes to go too straight in and create hinges.
Your terminations look pretty good though so you really just need to put more pressure straight in before popping the flake. More grinding strengthens the edge to allow more pressure to be put on it before the flake releases.

Here are a couple videos of a slab I worked with the square edge method.

https://www.youtube.com/watch?v=oDv_2C1txbA&t=97s

https://www.youtube.com/watch?v=lZtCWvSjcgU

[Stickhead]

Those videos are very helpful, 1442!  My first pass around the edges looked a lot like yours, but I can see that need to be more aggressive on the second pass to get bigger flakes.  Thanks!
...Tom

[Ryan Jacob]

If obsidian works anything like glass, then you can clear the face on the square edge with just your pressure flaker, though an ishi stick would help since from my experience, not using one does a number on your wrists. That or I’m doing it wrong.

[1442]

glad they helped stickhead

I recommend an ishi stick and squeezing it between your legs with both wrists braced on the insides of your legs. It takes a lot of force straight in to work slabs with larger flakes like that and it will hurt you if proper techniques aren't used.