The short answer: A shirt jacket is the more jacket-like layer; an overshirt sits between a shirt and a jacket. The names overlap. Fabric, lining and fit tell you more about how each piece wears. At Nicoby, the Sherpa-Lined Flannel Shirt Jacket has a faux-fur lining, while the Snap-Front Knit Overshirt is a textured knit designed to layer over a tee or under a jacket. Both sit in Jackets & Overshirts.
What makes a shirt jacket different?
Think of the shirt jacket as the outermost piece of a simple outfit. It borrows a shirt's collar and chest pockets but has the substance to finish a look over a base layer. Nicoby's sherpa-lined version uses flannel on the outside and soft faux-fur inside. It closes with snaps, including adjustable snap cuffs, and has two flap chest pockets with snap closures.
Its two colorways have different outer fabrics: Shadow is houndstooth flannel in a wool/polyester blend; Mocha is plaid flannel in a polyester/wool blend. The Shadow and Mocha blends differ, and this jacket also works beneath a roomier coat on cold mornings.

Where does the knit overshirt fit?
An overshirt adds a visible layer without committing to a lined outer layer. Nicoby's Snap-Front Knit Overshirt is a relaxed, over-fit textured knit with a spread collar, snap-front placket, two flap chest pockets and contrast woven trim at the collar and placket. Wear it over a tee or under a jacket. The knit is 56% polyester, 41% cotton and 3% spandex.

Choose by the layer you need
- Over a tee: Either works. Pick the overshirt when you want a textured shirt-like top layer; pick the lined shirt jacket when you want the lining and a more substantial outer piece.
- Under a coat: Both can sit beneath an outer layer. Leave enough room in the coat for whichever one you choose.
- For fabric and care: The shirt jacket's outer fabric varies by color and its care guidance recommends dry cleaning. The knit overshirt can be machine washed cold and tumbled dry low.
Look closely at the collar
For a different take on sherpa, see the Retro Plaid Jacket with Sherpa-Lined Collar; the sherpa detail is at the collar rather than throughout the body.
Want to compare all the available outer layers first? Browse Jackets & Overshirts.
