The fit of the Shirt
The Classic Fit
The classic fit is characterized by a traditional tailoring silhouette, allowing a comfortable fit with a boxier shape, with plenty of fabric in the sleeves and the body. It provides great mobility and features two pleats on the back, usually located near the yoke.
Since men in the mid-20th century would never wear a shirt without a jacket (or even a vest), the main priority was comfort. This is the go-to choice for those with a more classic style who favour comfort over fashion.
While a slim fit shirt is less comfortable and often more constricting in your movement, it is a lot more fashionable because it eliminates excess fabric. A slim fit shirt typically has an accentuated back with darts and a high armhole stance allowing for a shaped look that sits closer to the body, without being skin tight.
The modern fit falls in between the classic and the slim fit, providing the best of both worlds when it comes to comfort and style. A slightly tapered silhouette with the waist sometimes in combination with small back darts create a trimmer look than the classic fit that looks good even without a jacket without sacrificing comfort. The armholes are high, the sleeves have some room but are not too wide, and the yoke extends to or just past the shoulder bone.
Super Slim/Skinny Fit
This super slim or skinny fit is mostly popular with young men who think that tighter is better. In practice, this fit is usually characterized by lots of wrinkles, and unless you have a very skinny body that justifies it, you should avoid it altogether. Skin-tight shirts are not a flattering alternative for anyone, and they restrict the range of movement considerably.
Back of the Shirt
Apart from pleats or darts, you don’t have too many functional options in the back. Shoulder or center back pleats help to guarantee a large range of movement in the arms. Back darts, however, depending on their width, can produce a pronounced cinched effect on the waist that makes it slimmer and more contemporary. As with most details on the shirt, it all comes down to personal taste, although achieving a slim silhouette without resorting to back pleats might not be the easiest of tasks.