Ooblick is simply a mixture of cornstarch and water.
I poured in all the boxes of cornstarch that I could find in the school (which, luckily, was a lot since we like to get creative with potions often at our school) and added water. I probably had about three boxes in each table.
Unfortunately, I added too much water. The mixture was too watery and didn't get to that stage where it gets a bit hard until you pick it up and then it magically becomes liquid again making it so much fun to use.
We were out of cornstarch and I had eager explorers ready for some goo, so we added flour.
This did thicken things up a bit.
What I wasn't expecting was how much the children loved going from one sensory table to the other.....feeling the two mixtures, adding from one to the next. I really should have had the two tables directly next to each other.
It was another gloriously messy day learning science through our play.
Note: I did make sure to dump the mixture as well as wash the sensory tables outside as adding the flour made the potion more like a glue which could have caused problems to our plumbing.