Very Good Service from Swastik Penn... Platinum Blue Black is very good ink. Ink does stay blue as compared to Pelikan blue Black, which turns almost Gray. It is well behaved and have become my favorite. In fact Platinum has become my fav ink brand. I purchased 2 Bottles of Carbon Black, Blue Black and Lavender Black. All are wonderful ink, even though they are expensive. If they are a little cheaper, I may buy entire collection of Classic Platinum inks.