Time can ravage fabrics and render them absolutely useless. But, rather than sighing regretfully and then putting that special family dress aside, take it to someone who specialises in restoring old gowns. In England, that someone is Heirloom Couture.
Even if the dress seems to be beyond repair, Heirloom Couture will take key components and details from the gown you bring them and make something new from them. It doesn't, of course, have to be a family heirloom. Any vintage dress you take to them can have new life breathed into it.
In this age of cheap mass production, it's wonderful to find ways to hold onto, and use, precious things from our past.