Use only an acid-free box with acid-free tissue paper. Regular cardboard and tissue break down over time, damaging fabrics.
Select a box that is large enough. Cramming your gown into a too-small box or folding it too many times can cause permanent creasing and weaken the fabric.
Wrap your gown entirely in acid-free tissue before folding. Ensure that none of the fabric touches itself.
Line box with tissue before placing the gown inside.
Do not seal the box—many wedding preservation services permanently seal boxes for storage in order to keep air and dust out. But if you want to prevent permanent creases, or if you just want to take your gown out and admire it occasionally, make sure the box lid is removable.
Store your boxed gown in a dry, dark place in the main living area of your home, not the attic, basement, or garage. Textiles are very sensitive to changes in heat and humidity.
Condensation can also develop in sealed boxes, creating mildew and mold growth. Make sure your gown has room to breathe.
Take your gown out of storage every two years or so and air it out.
Re-fold your gown differently than it was folded before so that permanent creases do not develop.