Make Your Own Play Dough and a Porcupine Too

I've tried a few dough recipes, but they always seem a little too gritty. This one is smooth and soft - fairly close to the store-bought version - and stays amazingly soft and pliable even after being left out for hours (or overnight in our case).
Here's what you need:
1 cup flour1 tablespoon vegetable oil1 cup water1/2 cup salt2 teaspoons cream of tartaroptional:food coloringglitterscent - (