The following is information about possible discoloring of some products.
Our products are designed to resist staining under normal usage, however there is a possibility that some products may show a discoloration which is not related to staining. This is what we call “Acid Etching”, and can be much more obvious on darker colored products.
Acid Etching, from what we can gather, is caused by foods or drinks that have a higher acidity level, and are left to sit in the sink for an extended period of time. The acids in the food/drink will begin to affect the pigments of the sink and create a discoloration. This does not cause a weakness in the sink, and staining will not occur on top of the affected area.
Again, this is due to high-acid food and drinks that are allowed to remain on the sink surface for too long, and this is not currently an issue that is covered under our product warranty, as it relates to the end user using proper care and cleaning of the sink.