Contamination

Science lesson for the day.

The white lining in some of our sofa covers was showing up in the US with yellow stains in certain areas.  At first, I suspected a cat was sneaking into our factory and using the unpacked covers as a litter box, but after sniffing some returned pieces, the expert noses of our Thai staff confirmed it could not be cat pee.  

Without any other ideas, I took a sample to the local university to have a look at the stain under an electron microscope.  

The first image shows some moisture in the fabric.

This picture shows the specs of contamination, which the microscope determined was mostly Magnesium.

Apparently, after being loaded in a broiling shipping container the moisture formed condensation inside the plastic packaging and combined with some traces of magnesium, which was left in the lining after the moisture evaporated.   Now, we just need to find out where the magnesium came from.