These are the telltale signs of a fake Hermès Birkin, according to a vintage luxury expert with 20 years of experience

• A vintage expert with 20 years of experience says there are telltale signs to spot a fake Hermès Birkin.
• She said there are things counterfeiters don't put thought into, which can help reveal fakes.
• Here's what to look out for when picking out a vintage Birkin.

This as-told-to essay is based on a conversation with Koyaana Redstar, the head of luxury buying at Luxe Du Jour, an online luxury boutique for vintage designer handbags. It has been edited for length and clarity.

I was a nanny in college in Los Angeles, and I supplemented my income by going to Goodwill stores, finding designer handbags for low prices, then selling them on eBay or, at the time, Poshmark.

I enjoyed it, and I thought — I want to turn this into an actual job.

My mother told me there was nothing like the fashion industry in New York. She said, "You need to go to New York." And I replied, "Yeah, you're right, I do."

As soon as I graduated, I was there. In New York, I worked in a consignment store, where I got hands-on experience selling items from high-end luxury brands, such as Louis Vuitton, Hermès, and Chanel.

Since then, I've worked for Rebag, The RealReal, and other vintage consignment stores and have 20 years of experience in the resale industry.

I've learned strategies that help me identify specific things about luxury bags, from their model to configuration, just by looking at a piece.

To me, the Hermès Birkin and Kelly are possibly the most iconic bags in fashion. They are classic and retain value more than almost any other bag.

Here are tips on detecting if the vintage Birkin you're eyeing is authentic.

Zipper pulls

One of the things that counterfeiters don't often get right is the zipper pull. For some reason, most counterfeiters don't take the time or effort to get it right.

The zipper pulls inside Hermès Birkins and Kelly's are among the biggest giveaways.

With some fakes, when the word "Hermès" is pressed into the zipper pull, it almost looks bubbly, with a ridge on the edge of each letter.

You won't see that on authentic Hermès pieces — which will have crisp, clean letters on the zips.

Zipper Stops

There's also the zipper stop, which comes in the form of the letter H. Hermès changed that in the early 2000s — it used to just be a normal stop, and now it's shaped like an H.

If you compare fakes with real Hermès bags, you'll find that the real deal comes with a very specific shape of H. Counterfeiters will make fat Hs or skinny, tall Hs.

People who make fakes often overlook small details — like a zipper stop — which helps experts distinguish authentic items from fakes.

Fonts

Another thing that counterfeiters can't get 100% right is fonts — specifically, how it's engraved onto the hardware.

Luxury experts can tell a real from a fake because they've spent years looking at bag fonts — and knowing what common inconsistencies might surface.

One way to detect if it's fake is if the foil font stamped onto a bag has a green undertone. That's a telltale sign that something's amiss.

Smell

If you have a Hermès Birkin, you will know that the way the leather is treated gives it an almost perfumed smell.

But if you smell a bag and it gives off the heavy scent of leather — almost like a boot shop — that's not a good sign.

Hermès doesn't smell like that. So, if the bag smells too much like leather, it's a red flag. And if it smells like chemicals, that's even more of a red flag.

So I've taken to sniffing bags I appraise. I know it looks weird, but sometimes, the smell is a dead giveaway.