to me those looks like marks and indents made when pulled off the casting mold it was made in. Not sure.. hard to tell. Interested to know as I am looking to buy a Silgranite II Cascade.

It's hard to tell, but our Silgranit sink didn't come that way. I think your best bet is to contact Blanco customer service over the phone, and ask them where to email these pics and get their feedback on the pics.

I had those same marks on mine when I received it. There is a thread here somewhere and a Blanco rep responded...

found it:

http://ths.gardenweb.com/forums/load/kitchbath/msg0813080231703.html

Here is a link that might be useful: Blanco sink owners

Hello,
As a representative from BLANCO, I would like to add some information as to the quality and production of our BLANCO SILGRANIT kitchen sinks that may help ease your mind.
BLANCO is THE world leader in composite kitchen sink development in ALL areas of technical advancements, patent development, quality control, portfolio size, color offering, and true global production. Our products carry a lifetime warranty and are produced in BLANCO�s own factories located in Germany and Canada. Our sinks go through extensive quality control checks throughout each stage in production.
Specifically, I want you to know that each and every SILGRANIT sink�s underside does have some roughness and texture which may be interpreted as cracks. This is a natural part of our patented formulation and production process. The texture you are seeing on the backside is a result of the curing process of the material after casting. It does not in any way deter from the strength of the product but rather allows for the perfect combination of interior surface hardness and overall strength by ensuring that the maximum amount of granite is at the useable surface. It is this process that makes our sinks the MOST durable and the MOST hygienic surface available on the market today.
We pride ourselves on being a family company that focuses on quality, innovation, and customer service. We stand behind our products everyday with passion and pride to ensure you have a wonderful experience every time you use them. Please contact our customer care department at 800-451-5782 should you have any questions or concerns.

Had the same problem with

DO NOT buy ANY Blanco sink. PERIOD. I ordered one for my brand new kitchen and it came in cracked....as did the next 2. Now waiting on sink #4 to arrive. I would go to another option but my quartz has already been cut for this particular sink. I called the Customer Service 800# and they could not have been more rude. Blamed it ALL on the place I bought it and said they damaged it. Little did they know, the sinks were purchased at 2 different locations. Blanco has a Quality Control issue and they will NOT admit it. As far as the above statement that they pride themselves on quality, innovation and customer service, it has been MY experience that NOTHING could be farther from the truth.

@HU-451792833 - Please share where you bought these sinks. Were they authorized dealers of Blanco? If not, they could be selling seconds or returns, and/or not care about packing the sink properly. I agree with Blanco that usually the sink damage is caused by the online re-seller.

Interesting that you automatically jump on the side of Blanco. They were NOT bought on line. Two were from Ferguson Bath, Kitchen & Lighting Gallery, an authorized dealer located in Savannah, GA. The other from Home Depot, another authorized dealer. EVERY SINGLE SINK was packed with styrofoam and box was unharmed. Obviously they have a quality control issue when you read time after time people having the same issue with their sinks. BTW, this is a $500.00 sink and I would expect a better quality for the $.