In fact both the Li Ting Gui and Royal ink are made with premium oil soot. Oil soot is the type for calligraphy. Therefore, both are proper choices for professional calligraphy works. The Old Hu Kai Wen also categorised these two in the same group. The Li Ting Gui is a famous ancient oil soot recipe and it is named after the person who created this recipe. Its features have also been used for long as criteria to decide the inkstick’s grade. The Royal ink was in fact a special recipe for royal family. Old Hu Kai Wen was a royal warrant supply in Qing Dynasty. I think considering the strict rules for products supplied for royals, it should be a top inkstick too. Again, the difference is between the recipes but the recipes are confidential. 🙁 Unlike western art materials, fine Chinese art materials are difficult to mark the components, ingredients because most of them are secrets. For example, some of the top seal paste recipe is even marked as State Confidential Document. Of course, our inkston Xuan papers are also made with our own recipes. 🙂 Therefore, for the papers, we can mark some basic information.
I was also looking for the best inkstick to choose for calligraphy and seriously considered both these excellent inksticks. One of these will very likely be my second purchase but I picked the Jin Bu Yi Fine Oil Soot Black Inkstick for my first. Once my poor efforts and practice make me more worthy one of these will head my way.
For calligraphy, you need dark black and fluidity (not too sticky ink). The both inks Li Ting Gui and Royal ink are correct. I often use also japanese inkstick that are excellent but much more expansive. This is for oil soot ink. But if you want to copy ancient calligraphy masters on a “looking old” paper, I advice you to use a good pine soot ink, in order to get deeper dark instead of too glossy strokes, particularly if you practice xiaokai on a shuxuan paper, because when the ink does not penetrate the paper and dry on the surface, it becomes more brillant.