How do you secure your plastic down? That’s one issue I seem to have with thin stock.
Looks like Joseph used tabs, like a stencil to hold the pieces together/down.
Other techniques:
A downward spiral bit
Double sided tape or carpet tape
I was more wondering about how he holds down the enitre work pieces. There looks to be just some typical hold down clamps, but I find with thin material it wants to pull up on the bit the further away from the clamps the bit gets.
i just clam it down where i can and watch it cut if i need to hold it i do i cut thru in one pass no tabs
IMHO a downward spiral really helps with thin material since it applies a constant downward cutting force.