It's hard to imagine a handbag market in which most Chanel flap bags aren't festooned with interlocking CC locks, but until Lagerfeld added them to the bags and spun off the Classic Flap in the 1980s, Chanel's flap bags bore the logo-free Mademoiselle Lock the 2.55 Flap Bags hold today. The Mademoiselle Lock gets its name from the fact that Coco Chanel never married.
​
Chanel's first bags had all-chain straps, but the story goes that Coco subbed in leather-filled straps when resources were scarce; over the Chanel Flap Bags' histories, several different types of chains have come and gone. Classic Flaps only use leather-woven chain straps, though, and modern 2.55s only use all-chain straps.
​
The 2.55's interior was inspired by orphans. More specifically, the shade of burgundy leather that has long been used to line the original flap bags (as well as some Classic Flaps) was chosen because of the uniforms worn by Coco and her fellow charges at the convent orphanage where she was raised.
​
Chanel flap bags owe several debts of inspiration to men. Chanel's signature quilting was purportedly inspired by the jackets worn by male stablehands that Coco was particularly fond of. Also, Chanel's most recent flap bag line, the Boy Bag, was named after and inspired by Coco's longtime lover, polo player Boy Capel.
​
Chanel's Flap Bags have one of the more confusing taxonomies in handbag history. First and foremost, the Classic Flap refers to the Flap Bags with CC locks that follow the design conventions Karl Lagerfeld debuted in the 1980s. The 2.55 refers specifically to Coco Chanel's original design with the Mademoiselle Lock, but is often used as a catch-all term to refer to all Chanel Flap Bags that use the brand's traditional structures.
​
A 2.55 flap bag only cost $220 in 1955. Chanel bag prices have skyrocketed over the years. Plain leather versions can now retail for as much as $6,000; that increase surpasses the rate of inflation just a bit.
​
The hidden zipper compartment has a special back story. Under the top flap, Chanel bags have a weird little zipper compartment that you won't find in bags with similar structures from other brands. As the story goes, Coco hid it there to have a secret spot to stash her love letters. She was having a rather torrid affair at the time.
​
Chanel's flap bags are a pretty decent investment. Because Chanel constrains its supply, regularly raises prices and has a long history as a luxury favorite, Chanel bags are a favorite on the resale market. Hard-to-find seasonal versions in like-new condition regularly sell for above their retail prices, and even gently used bags in regular leathers tend to hold their original value very well. There's relatively little risk in splurging on a flap bag, whether it be the classic flap or the iconic 2.55 flap.

Source: smithsonianmag.com