Many things pass through our sinks over the years our dishes and utensils as well as the food we eat. With so much use, it is important for our sinks to stay clean and cared for. Old sinks tend to collect dirt and grime more easily and can lose their shine and luster. Proper cleaning with the right materials will restore an old white kitchen sink to cleanliness and beauty.
I've had stainless steel, enamel coated cast iron and corian sinks. Each as an advantage for cleanliness. All require routine cleaning. I found the stainless steel easy 'cause I would come back nice & shiney clean after scrubbing with a comet-type cleanser. The same was true for enameled cast iron but I was annoyed by the marks pots would leave. I switched to corian then, to avoid the seams. I use a soft-scrub type cleanser to scrub it clean but over time it has slowly gotten a bit yellower. Its an off white so not hugely noticable. This is after about 12yrs. I'm going back to the enameled cast iron I think.
I have a composite granite sink. I love it. it is black and no stains or dirt show (but I have to assume it is there) VERY easy to clean and every now and again - I throw some polish on it and it gleams.