This is a common question. Because it depends on many factors.
The rule of thumb is one and a half times your seating, however that does not leave a whole lot for anything else.
Because you will want to promote your business with your menu, I would recommend that you print your restaurant menu using a high grade of material, like the EndurAce material (a water resistant surface for longevity), then add a less expensive delivery grade printed menu for promotions.
You'll want to send your menu to the businesses in the area around your restaurant as well as to writers/media, hotels, etc. So don't scrimp, make sure you have enough to go around. Your menu will be the driver of your traffic.