In a blender, combine the flour, milk, melted butter, eggs and 1/2 cup water. Pulse for 10 seconds. Place the crepe batter in the refrigerator for 1 hour. This allows the bubbles to subside so the crepes will be less likely to tear during cooking. The batter will keep for up to 48 hours.
Heat a small nonstick pan. Add butter to coat. Pour 1 ounce of batter into the center of the pan and swirl to spread evenly. Cook for 30 seconds and flip. Cook for another 10 seconds and remove to a cutting board. Lay the crepes out flat so they can cool. Continue until all the batter is gone.
After the crepes have cooled, you can stack them and store in resealable plastic bags in the refrigerator for several days or in the freezer for up to two months. When using frozen crepes, thaw on a rack before gently peeling apart.