Manufacturing Mayonnaise Jars

Mayonnaise jars are particularly difficult to manufacture because they are filled with mayonnaise, which is white. The mayonnaise will highlight any black spots and/or defects in the glass. Mould swabbing compounds are typically suspected as being the primary cause of black spots. Improperly using a swabbing compound can result in black spots. However, there are many other sources of black spots which have nothing to do with swabbing. This paper outlines some thoughts on what causes black spots and what can be done to eliminate them.