I heard good words about Comso but I can't testify. However I used the Ceulemans on many occasions. It's from the same factory that produces Masters, Buffalo, etc chalk. However, in Masters you have good ones and less good ones. The Ceulemans one seems more quality controlled and every cube I used so far has a really fine powdered grit.
So it's good basic chalk, better than regular Masters. I'd put it up against the Blue Diamond for sure.
However, don't expect it to be next level Kamui chalk.
