One sign of a high-quality dress shirt is natural buttons. Plastic buttons are cheaper and more durable than mother of pearl, but they lack the natural pearlescent sheen of the Real Deal. The difference is marginal, but it’s one way a fine shirtmaker distinguishes his product.
If you’re not experienced at spotting natural buttons, there’s an easy way to test. Grab a sleeve, and touch the cuff button to the top of your upper lip. at the bottom of your philtrum. (I use this spot because putting it on the part of my lip I use to eat is kind of gross.)
Natural buttons are more conductive to heat than plastic ones, and will feel cold against your lip. The difference is marked, and easy to feel.
The real trick, of course: explaining to store clerks why you keep eating sleeve buttons.