I took an old small (1L?) platy, cut it down, and marked the bottom with 1/4, 1/2, 3/4, 1, 1 1/4, 1 1/2 cup marks with a Sharpie, then put tape over the marks to ensure they didn't wash away. It's a standard part of my cook kit, a 'measuring cup' that weighs next to nothing. Quite handy.