His production team spent months whipping up different batches of the corn syrup/glycerine mixture to get the right formulas.
It needed to ooze in some instances, glide in others.
I had no idea how complicated it would be, says production designer Jefferson Sage (Spy).

Credit: Hopper Stone
The special effects guy would mix up batches and play with it.
Then he would make videos dumping slime on the ground, squirting it out of a hose.
We needed to know what it does when it hits something.
What happens to it when it drips down a wall?
It makes a mess.
Here, they venture to explain how it felt.
But as you give a shot to wash it off, it regenerates.
So the more you make a run at wash it off, the slippier it becomes.
LESLIE JONES:Its terrible.
Its like that slime stuff they used to sell in a little jar.
MCCARTHY:But it has a viscosity as you touch it, like the hair goop from the 80s.
KRISTEN WIIG:With a little bit of mucus.
MCCARTHY:And a whisper of vomit.
KATE MCKINNON:Its like if you have dry mouth and you buy that fake saliva.
MCKINNON:Oh, yeah.
you could buy spit.
you’re free to get anything nowadays.
Ghostbustersopens in theaters on July 15.