For the finishing touch on your Charles Dickens, Phantom of the Opera, or Abraham Lincoln costume, there's nothing like a top hat. Unfortunately, top hats are expensive, and if you have a hard-to-fit head (either large or small), nearly impossible to find.
However, with a little ingenuity and a couple hours' work, you can have your very own custom hat for almost nothing.
Things You'll Need
Black poster board (2 sheets)
Hot glue gun
Black satin or velveteen fabric (optional)
Start with the brim. Determine how low on your head you want your top hat to rest, and measure the circumference of your head at that point. Draw a circle on the poster board that has the exact same circumference as your head. Top hat brims are about two to three inches wide, so draw another circle around the first one up to three inches away, depending on your brim preference. Cut this ring out of the poster board.
Add the "stovepipe." How tall you want your hat is up to you. If you're going for a comic Mad Hatter look, the taller the hat, the funnier the look. Actual toppers, though, are generally between eight and ten inches high. Cut a rectangle out of the poster board that is as wide as the height you want, plus one inch, and as long as the circumference measurement of your head, plus one inch. Curl the rectangle into a circle and set the resulting "stovepipe" into the circle of your brim. It should fit perfectly. Attach the short sides to each other with either hot glue or staples. Be aware that once it dries, hot glue will not snag strands of your hair. Slide the brim up one inch from the bottom of the stovepipe.
Carefully snip into the stovepipe one inch every inch all the way around the bottom of the stovepipe. Fold the resulting little flaps so they rest against the underside of the brim, and glue into place.
Top your hat. If you were careful when you cut out your brim, you should be able to use the circle you cut away as the top of your hat. If not, turn the hat upside down onto another part of the poster board and trace the circle you need to cut. Add an inch all the way around and cut the circle out. Again, carefully snip one inch every inch all the way around the circle and fold the little flaps over. Secure the top of your hat to the stovepipe by gluing down the little flaps on the inside of the stovepipe.
If you want to make your poster board top hat even more realistic, cover the outside with black satin or brushed velveteen fabric. It will give your hat that authentic nineteenth-century touch.
Be liberal with the hot glue, especially on the inside of the hat; it will hold better and it won't be seen.