I have been using Inkston for the past few months and I must say the overall service is excellent. I receive the products ordered in roughly the expected time, i.e. about two months or a bit less (I live in Milan, Italy). People are always available for any query that you receive immediately or in less than 24 Hrs.
I have ordered some liquid paints in glass jars that I have started using and they seem fine. They are loaded with pigments and you need very little to get the right hue and intensity. One jar out of ten leaked because of airplane pressure variation, but they promptly gave me a refund.
I’d strongly suggest Inksone both for the quality of their products and their service.