ARRRGGGG! Where is my son when I need him? Oh yeah he's in school. He is a boy scout and could answer this question. I used to know it (all that inherant knowledge from being the mother of a scout) but I forget. If I get a chance to ask him before the day is over I will repost an answer to your question.

here's the official text: A properly proportioned flag will fold 13 times on the triangles, representing the 13 Original Colonies. When finally complete the triangular folded flag is emblematical of the tri-corner hat worn by the Patriots of the American Revolution. When folded no red or white stripe is to be evident leaving only the honor field of blue and stars. There doesn't seem to be a specific reason, other than neat appearance and the fact that if there is any stripe portion showing, it hasn't been folded perfectly.

Flag folding has been around ever since there were flags - long, long long before the Revolutionary War. The triangular fold we teach Boy Scouts, used by the military honor guards, is actually a naval invention. Flags folded in that fashion can be attached to a lanyard and hoisted immediately — and the flag will neatly unfurl as it goes up. We use the fold on land for the same reason. It’s a traditional fold that predates our flag. "If the flag in its prescribed dimensions is folded correctly, there will be 13 folds." WRONG Were the flag longer, or narrower, there would be more. From having folded the flag several hundred times, I can tell you that it is completely unnecessary to count the folds in the process. If the folds are too loose, it becomes apparent within a couple of folds. Flag folds have no official symbolism: One may create a flag ceremony that talks of American values, but it is complete hooey to claim that there is any particular symbolism attached to folding the flag. Flag etiquette, for years the domain of the U.S. Marine Corps, the American Legion and the Boy Scouts of America (BSA), is now prescribed by a section of U.S. law (without teeth) generally known as the U.S. Flag Code, 4 USC 1. Were there official symbolism to folding the flag, that is where it would be prescribed. Checking the law, we find no such symbolism. The U.S. flag code does not prescribe or describe any method of folding the flag. Any resemblance of a triangle to a tricorn hat is purely coincidental. We already noted that the folding procedure preceded the American Revolution. No one, at any time, made a search to find a way of folding the flag to resemble a tricorn hat. Nor for that matter were tricorns supposed to resemble a folded flag. A tricorn hat adorns the statues of the Minutemen in Massachusetts, but far from all soldiers in the Continental Army wore them — some Virginians probably avoided them as crude affectations by the backwards, unrefined New Englanders (see David McCullough’s wonderful book, 1776). Read more: http://timpanogos.wordpress.com/2006/07/19/fisking-a-flag-fold-flogging/