If you live with treasured antiques, treat them as you would like to be treated. Artifacts made of fabric, wood, paper, or plastic are safest in the same conditions that make humans comfortable. Anything else is destructive.
Keep them with you-you wouldn’t want to live in a hot attic or damp basement, and neither do they. Give them climate control. Most will be fine at any temperature you find comfortable. Watch out for summer humidity that causes mold, and the dryness of winter heat that causes cracking.
If you enjoy a comfortable bed with nice sheets, so will your treasures. Textiles in particular like a soft, well padded resting place, while books and papers like firmer support. Fold textiles with tissue supporting each fold, and don’t crowd them in a small box. Books with sturdy spines should stand at attention with large bookends and no leaning. Those with week spines should rest horizontally, as you do when sick. A beloved book that is actually falling apart should be in a close-fitting box.
For tissue paper and boxes, use acid-free materials. They are labelled as such and have been specially manufactured. Refresh the bedding as needed. Just because a material starts acid-free doesn’t mean it stays that way. This acid does not dissolve your treasures, not for quite a while, but can cause unsightly color change.
Beware the sun! It changes other materials just as it does your skin. It can darken paper and fabric, make a photograph crackle and flake, and make objects made of celluloid, the first plastic ever invented, spontaneously combust! That last one is rare, but interesting. Display treasures away from direct sunlight, or protect them with “sunscreen,” such as window films and framing materials that block UV rays. Fluorescent light is just as bad.
Do you bath in caustic chemicals? Don’t send antique textiles to the dry cleaner. If one really needs cleaning, if its dirtiness goes beyond adding a bit of character and is distracting or damaging, treat the textile like a baby. Use a gentle soap. Orvus is good. Quilters trust it. Use warm water and no rough scrubbing or ringing. Must you iron? Can I talk you out of it? Use the coolest possible temperature, and a piece of unbleached muslin between the iron and the textile. Ironing mistakes are pretty close to fatal.
Do-it-yourself surgery is a horrible idea! Call a doctor. Professional conservators, (find a local one here) know how to repair things the right way, and they know when to leave well enough alone.
Sometimes the best answer is just to stop the process of deterioration to extend the artifact’s life. That might involve supportive fabric added to the back of a fraying, rotting textile to keep its remaining parts attached. The result won’t look new-it will look like an object that has survived a long history and is ready to go forward. Keeping them around a little longer is the point.