In a blender or food processor, whirl the eggs, flour, and milk until batter is smooth; scrape container as needed.
Use a crêpe pan or regular or nonstick frying pan with a bottom that measures 6 to 8 inches across. Set pan on medium-high heat; when hot, brush bottom with butter (as needed or for flavor, in a nonstick pan).
At once pour a measured amount of batter into the hot pan and tilt to coat bottom: For each crêpe, use 2 1/2 to 3 tablespoons for a 6- to 7-inch pan, 3 1/2 to 4 tablespoons for an 8-inch pan. If heat is correct, crêpe sets at once, forming tiny bubbles (don't worry if there are a few holes - if they are large, fill with a drizzle of batter). If pan is too cool, the batter does not bubble; increase heat slightly. Cook crêpe until edge is lightly browned and surface looks dry, 30 to 60 seconds.
Run a wide metal spatula under crêpe edge to make sure it is loose in the pan. Turn crêpe over with the spatula and brown lightly on bottom, 5 to 10 seconds. Tip pan over onto a flat plate to release crêpe. Repeat to cook remaining batter, stacking crêpes on the first.
Nutritional analysis per 6-inch crêpe.