Converse All Stars claim to be the "classic sneaker." So I was surprised to see a patent number printed inside my new pair of shoes. What innovative technology could possibly be found among a few swatches of rubber and canvas?
I was even more surprised when I looked up the patent. The patent (6,430,844) is for an invention on house slippers with fabric bottoms, not sneakers with rubber soles.
Then I looked closely at the soles of my Converses. At first I thought I must have stepped in something. But after I had read the "fabric" patent, the spotty patches of fuzz on my shoes now merited a closer look. Under a microscope, the fuzz appeared to be embedded in the rubber of the soles. It could no longer be explained as, say, some sticky mix of drier lint and spilled Coke. Was this fuzz actually the "fabric" described in the patent?
But why would someone invent sneakers that make it look like you have taken a careless walk through a laundromat? Does the fuzz somehow improve traction, like the microscopic hairs that let geckos climb on walls? That didn't seem likely. The fuzz appeared only around the perimeter of the soles and under the arches: areas that support the least amount of weight and have the least need for traction. Does the fuzz improve the wear of the soles? No. By the time my shoes were just a couple of months old, much of the fuzz had eroded down to bare rubber.
When I looked at other patents from the same inventors, I finally found an explanation.
Since my shoes were made in China, they were subject to an import tariff when they were shipped to the United States. And the import tariff is much lower for shoes with fuzzy fabric soles (like house slippers) than it is for shoes with rubber soles (like sneakers). According to the inventors, changing the shoe material can lower the duty from 37.5% down to just 3%. (6,471,491)
To benefit from a lower tariff, it isn't necessary to cover the entire sole with fabric. According to the inventors, "a classification may be based on the type of material that is present on 50% or more of the bottom surface." (6,471,491) This explains why the "fabric" fuzz extends mostly around the edges of my shoes, where it can take up a lot of area without interfering too much with the traction of the bare-rubber centers.
So the invention embodied in my shoes is not a technological advancement. It actually seems to be a small step backward in quality. Instead, my shoes embody an advancement in "tariff engineering." But perhaps, by putting up with a bit of fuzz, I can pay just a bit less for each new pair of sneakers.