Liquid and powder aren't a contractor's only choices when considering release agents for concrete, and Richard Smith's contracting company seems to have explored many of the alternatives.
They've used ground seashells, 120-grit silica sand, and all kinds of aggregates.
Decomposed granite residue is "just dirt, for the most part," Smith says, but as a release agent it gives a slab the varied hues of real stone. Shells, when used with a rough stamp and a limestone color, leave behind concrete that looks like an exposed fossil bed. Making one thing look like another is what decorative concrete is all about, Smith says. "We're trying to simulate and emulate the real thing."
On one job at the home of a famous Hollywood couple, Smith's firm put down thousands of dollars worth of 1/8-inch and 1/2-inch dice as a release agent. At one point, the couple asked if every little die could have the same number showing. "We get a lot of weird, weird requests," Smith says.