Thank you for viewing! I've gathered buttons, mostly 1.2cm in size. I believe this is the size for most shirt and polo shirt buttons. Even at 1.2cm, you can see the thickness of the button itself! I didn't know that! Apparently, the reason buttons are difficult to pass through buttonholes or easily come undone when replacing them is because of the difference in thickness. The size is not measured using a scale, so please consider it as an estimate.