But it is both 18mm and 6mm narrower, so it goes from 1.414 to 1.29 in terms of ratio. In other words A4 seems 10% narrower in terms of shape, which isn't insi

But it is both 18mm and 6mm narrower, so it goes from 1.414 to 1.29 in terms of ratio. In other words A4 seems 10% narrower in terms of shape, which isn't insignificant. Having said that, I'd rather keep A4 given the useful properties described in the article.