I did a screenprinting workshop a long time ago with some people from Lavazza coffee.
I wanted to show them that you could use coffee to screenprint onto t-shirts (it worked, but only after I printed a layer of transparent base over the top).

So I spent ages making espressos as thick and as gloopy as I could. My old Krups espresso machine was going non-stop, my whole studio stank and I started getting twitchy from all the caffeine floating about.

I did the different types of coffee into different tubs, to see which worked best.
This is two of them I rediscovered on a studio clear-out.