I was unpacking some sport coats after getting my luggage back from a trip and I discovered this on the sleeve: It's only on the surface, appears slightly fibrous, and no similar spots were found on any of the other clothes in the suitcase. A matching discoloration can be seen on the facing fabric. I looked around for other anomalies in the suitcase and could not find anything. My first thought was some sort of spider or insect must have made it but I really have no idea. Anybody else see something like this before? And for those interested it is a 1980s Hart Schaffner & Marx "rescued" from my dad's old wardrobe. Fits quite nicely.