I’ve been wearing vintage clothing for almost a decade now, and I’ve enjoyed every moment of it…except for the times when I destroyed several exquisite pieces simply because I didn’t know how to look after them. I’ve ripped seams irreparably, let old leather dry up, crack, and mildew, and ruined silks with hot irons. As a result of missteps like these, I eventually learned to take better care of old garments, which, in a way, are similar to old people: They’re fragile and sometimes temperamental, but often come with utterly fascinating histories. So now I’d like to pass my methods on to you so that you can protect your own thrifted treasures! Here’s everything you’ll want to keep in mind to make your vintage last forever.

Materials

The first thing to figure out about any piece of vintage clothing is what it’s made of, because that will tell you how delicate or temperamental it is. New clothes generally announce their makeup on their labels, but those tags are often missing from vintage stuff. If you’re not sure what material a particular piece consists of, try asking your local tailor or dry cleaner or another professional in the know. Here’s a breakdown of some of the most common fabrics you’ll come across in your thrifting:

Polyester: This thick knit, which first became popular in the 1960s, is one of the sturdiest fabrics around—I own quite a few ’60s scooter dresses, and all of them are virtually indestructible. Go ahead and wear the fuck out of your poly-knitted pieces, because they’ll last forever no matter how frequently you wear them. Polyester is built to last!

Natural fibers like wool, cotton, and silk: If your tastes are more inclined toward pre-1960s loveliness, keeping your vintage wardrobe in tip-top shape is going to be a little harder. Most clothing from the first half of the 20th century is made from natural textiles that become increasingly delicate with age and therefore require careful maintenance. Look for pieces blended with rayon—they’ll be sturdier than 100% natural fibers. But even the most perfectly preserved deadstock from the ’50s and earlier isn’t likely to withstand everyday use, so be careful when choosing when to wear these treasures.

Vinyl or PVC: It’s possible to find wearable vinyl if you’re willing to search, but don’t buy anything that’s cracked, sticky, or flaky. After a vinyl or PVC piece has started to deteriorate, nothing will slow its speedy demise. When I discovered the glorious world of eBay, I happened upon a collection of deadstock vinyl Golo boots. The seller had issued a very clear warning that the vinyl had cracked, making them unwearable, but I was so taken by the idea of owning a pair of original Golos that I bought them anyway. Predictably, my dreams of mod authenticity were dashed when they arrived in the mail and then promptly fell apart. The moral of this sad story is that we should all heed warnings on eBay! To ignore them is to invite heartbreak—especially with irreparable materials like these.

Leather: There’s a fine line between “worn” and “beyond redemption.” A bit of wear looks great on vintage leather, especially leather jackets, boots, and brogues, but if the piece in question is visibly withered or dry or otherwise looks like the last good day it saw was decades before you were born, it’s best to move on.

Fit

If you buy a cotton T-shirt one size down from your regular size, it will be tight, but maybe that’s what you’re going for, and the T-shirt won’t mind. But if a vintage piece in a delicate fabric is tight on you, the tension at the seams and across the fabric might be too much for it to withstand. Vintage seams can be very fragile, especially in natural-fiber pieces. Once they rip, it’s very hard to repair them.Depending on the era and the country of origin of a vintage piece, I can go up five or six sizes from my normal modern-day one—and the older a piece is, the smaller it will be in relation to the number on the label. This is why you should always try things on before buying, to see if you’re able to move freely in that dress or those hotpants.

If you’re buying online and can’t try something on, knowing your measurements will help you tremendously. or a long time, I couldn’t buy anything larger than a specific number without triggering all my fat-girl insecurities, so I’d end up with a lot of vintage clothes that almost fit me. Soon enough, the seams would start to fray, and I’d know the dress or whatever was a goner. Since then, I’ve realized that neither my body’s real size nor my self-confidence are in any way affected by my dress size, so now I always add an inch to my real measurements when I’m considering buying a piece online. Better a garment be a little too big—you can always get it taken in by a tailor—than too tight.

Here’s a handy guide to taking your own measurements.

Washing

Putting your wardrobe through the spin cycle is handy if you’re into indestructible and easily replaceable clothing, but that can spell death for older or more delicate finds. Hand-washing extends the life of older clothing exponentially. Here’s how to do it:

First, soak your clothing in warm water (one exception: silk can’t handle anything hotter than room temperature). Then add detergent or, if you’re working with natural fibers, shampoo. This is gentler on very delicate materials, many of which (silk and wool, for example) came from living things. You wouldn’t use Tide on your hair, would you? Don’t use it on wool, either. Once you’ve added your cleanser, leave the clothing to soak for a good long while—extended baths are great for getting funny smells out and make stains much easier to remove—do the latter by spot-treating the blemishes with a cleanser or stain remover tested beforehand on a hidden part of the garment to make sure it won’t damage the material. Then dab that product on the stain and let it dry completely before washing the whole piece. Rinse everything with two loads of fresh water, then squeeze the excess moisture each garment gently. Handling wet clothing roughly can damage it, so never, ever wring it out—and if the clothing you’re washing is particularly old and frail, forego the squeezing altogether. Finally, hang your freshly clean vintage out to dry anywhere you want. Just make sure it’s a safe distance from radiators or other any other source of direct heat, which can damage your lovingly cared for garments.