Your 40th birthday invitation should reflect the type of party that you will be holding. It should be informative and creative enough to encourage guests to show up at your celebration. Keep in mind that the success of a party starts with how effective your invitations are in convincing guests to attend it.

The 40th birthday invitation that you are going to send out should give an idea of what type of party is going to be held. Is it a formal event or a casual one? An outdoor get-together or a party at an exclusive venue? To help you design your invites appropriately, here are some pointers.

1. Formal event. If you are holding a sit-down formal dinner, the invitations should be simple and subdued in design. If the event calls for a black tie or formal clothing, make sure that you put that information on the invitation. Invites for formal dinners are usually comprised of a special paper of white or cream color. Commonly, only two colors are used (three at the most), the color of the paper and the color of the ink. Words that tell of the when and the where should be there also. If you wish to add a few personal notes, keep it serious and simple.

2. Informal event. If it's a casual get-together, then you can add more shades or colors and use fancier designs. But remember to tone it a bit since guests will likely belong to the same age group as the celebrant and kaleidoscope designs might be less appreciated by this age group. Choose the design that represents the celebrant best but also gives an idea of what type of party will be held.

3. Invitations for him and for her. For women celebrants, pastel shades are ideal, while male celebrants would likely prefer earth colors or shades of blue. In any case, ask the celebrant's preference, unless it's a surprise party. Again, don't play too much with colors. Three shades should do it.

4. Consider the invitees. If your party will be attended by both close friends and colleagues, you might need more than one set of invites. The invitations you will send to special friends and close relatives might not be suitable for guests like business people or politicians or other high-profile invitees, particularly if you made the invites for personal friends more casual than the event calls for. If you have the time and resources, create at least two sets, one for those who will understand the less-than-formal message and one for the people who only see you in your business suit.

In designing or choosing a 40th birthday invitation, make sure that you consider the nature of the celebration and the people who will be attending it. Don't just pick something that you see on the shelf, give it a bit more thought. Forty, after all, is a landmark event and it should be treated as such.