Many years ago, I bought bespoke shirts from Jermyn St, which is the ‘shirt street’ in London. One thing I noticed was that they had a horizontal buttonhole at the waistline.
This is perfect if someone is even slightly overweight because that buttonhole takes the strain much better than a vertical one.
I don’t do this with many of my shirts but I suppose it is part of the history of shirt making – and will be very useful if I gain any more weight.
I’ve worn this shirt many times and the horizontal buttonhole is withstanding the strain much better.