mud on one's boots

An allusion to various lines of work where a person is physically present on site, e.g. construction as opposed to architectural design.

mud on one's boots (uncountable)

1. (figuratively) Practical experience.
   • 1966, Teaching Engineering Design: Proceedings of the Conference on the Teaching of Engineering Design held at Scarborough between 13 and April 1966

     The civil engineer, for all his skills, is still often known as the man with mud on his boots.

   • 2001, Stephen S. Saucerman, Moving to Commercial Construction (page 96)

     I used to place architects on a higher level, well above someone like me who works with his hands and gets mud on his boots.

   • 2008, Kenneth Allinson, Architects and Architecture of London (page 390)

     Cook never attained meaningful practical experience, but Herron loved site mud on his boots.