Here are a few useful guidelines that even non-experts can use to assess the quality of a shirt.
Signals of a good shirt include:
– French seams
– Hem gussets
– Misalignment under the armscye
– Non-fused collar
– Quality and stitching of buttons
– Horizontal stitching on the last buttonhole
Today, shirts have two types of seams: French seams (strangely translating as couture anglaise – British seams in French) and double stitched seams.
Located on the sides of the shirt’s body, inside the sleeves and at the armscye, they give an immediate and reliable idea of the care put into the construction.
Simply put, double stitching (the most common stitch because of its simplicity) is done by simultaneously threading two needles into two superimposed fabrics. The result is a flat seam on which the two threads are clearly visible. It is the “cheapest” seam (90% of the time machine sewn) and the least sophisticated.
Conversely, only one thread is visible on the more refined French seam because the other is inside the shirt. The tailor sews a first row of stitches inside the shirt (right side in) and folds it in to sew the second stitch on the outside. This is what makes the French seam assembly so delicate, characterized (and easily recognized) by the small “bump” it leaves along the fabric.
Because it is increasingly rare (even among “great” English shirt makers), the French seam almost always indicates a good quality product. It is always used by great Italian shirt makers and by a few labels particularly mindful of the flawless quality of their products (like, for example, Marc Guyot in France).
Hem gussets are the small fabric triangles that bind the front and back of the shirttails to reinforce the junction. No longer only found on made-to-measure and bespoke shirts, hem gussets are now seen on some RTW, particularly on superior quality products, yet are not always exclusive to high end shirts.
This assembly technique is less and less common. It involves a slight imbalance in the sleeve symmetry and prevents gaping at the junction point of the underarm stitches. This type of construction makes ironing much easier and significantly increases comfort.
Today, fusibles are present in nearly 90% of the market. Even great labels use it (with quality interfacing) because, among other reasons, it makes ironing easier, preventing the formation of a small crease when the extra cloth is pushed to the edge of the topstitch when pressed.
For aesthetes, a non-fused collar translates into a higher quality shirt, where the neophyte may see a flaw. In high temperatures, the non-fused collar also helps the skin breathe better and is a lot more comfortable.
Lower quality shirts have plastic buttons, and higher quality shirts have mother-of-pearl buttons. The very best quality buttons are made of Australian mother-of-pearl and are delicately flamboyant.
Button seams are another very good gauge of shirt quality, ranging from classic (two parallel rows) to a croce (cross seam) or the famed zampa di gallina (chicken feet in Italian, see image above, far right), a method that is prized by the best Italian shirt makers.
Ultimate purist detail: the last buttonhole is sewn on horizontally (see image above) to avoid tensing the buttonhole seams inside the trousers.
If you happen to read French, you can go into more detail by visiting the following excellent resources :
Bonne Gueule : comment reconnaître une chemise de qualité
Forum En Grande Pompe : Histoire Pacifique des Boutons
Et bien entendu, la section du Guide PG des Maisons de Qualité consacrée à la maison Courtot