This time of year, after weeks of holiday feasting, your pants might be fitting a little snugger than usual. (No judgment here!) But if you wear dress pants — particularly slim-fit men’s dress pants — it’s nearly impossible to find perfectly fitting trousers. 

As menswear writer Derek Guy recently explained on the social media platform, X, that’s because a crucial part of the tailoring process  — ironwork  — has been almost forgotten in the modern era. 

Click the audio player above to hear Guy explain what that means for today’s fits.