FWIW...
PeteLind45:
...two wires attached to aluminum foil separated by velostat...
is not an on/off switch. It's a variable resistor whose resistance varies with pressure.
To make a momentary contact switch, see the "button" instructions in the PDF in post #2 (BTW, it doesn't involve Velostat).
That's not to say that Velostat couldn't be used as proposed, but if you go that route, you would have to consider the sensor resistances, how much one changes with pressure, determine the other voltage divider resistor value, and what analogRead() level to trigger on.