Why do boots leave clean prints on tent fabric?

Compiled by Juli Case

When we’re cleaning our tents, which are made out of vinyl laminate, we sometimes notice something odd. The tents are dirty with this brown-looking film that takes a lot of work to get off with a brush, but if one of the guys walks across it with his boots on, it cleans the fabric perfectly, leaving ‘clean’ boot prints on the fabric. Why is that?

There are probably a number of contributing factors causing what you’ve observed. For one thing, the soles of boots are usually made of rubber or some other nonskid type of material. The same characteristic that makes the material nonskid means that it will grip the fabric better than a smooth surface. It’s the same reason that squeegees used for cleaning are made of a similar material. Another factor to consider is that while a brush has a lot of bristles, the surface area of each is pretty small. The surface area of the bottom of a boot is much larger, and it has that much more contact with the fabric. In addition, the weight of the adult wearing that boot is likely more than the force that can be applied to a brush, making the nonskid surface area (already larger) more efficient. Finally, depending on the environment in your area, it could be that there is a pollutant in the area that has a chemical affinity to the boot sole material.

Juli Case is IFAI’s information and technical services manager.