I look forward to own a fountain pen and I would like it to have certain features. I would like it to be cartridge refillable, and I would like it to be oblique and triple broad at the same time (O3B). I am an orthodox person and I wouldn't like to grind it, because of personal concerns. I have also been told that italic pens have good variation in lines and I would like to add that feature to the nib. If all of this is not possible together, I would love to receive any feedback for a close pen to what I have in mind, I like thick lines and I love variation too. So it could be also OBB, BB, or any italic with good wide. I don't want to spend too much money in a pen but if I have to do it I will, please drop any recommendations you may have for this not to be that expensive. I really would like to have a pen that is easy to go, that's why I prefer cartridges instead of pistons. I know that really good fountain pens don't come cheap, modern, or some even in cartridge versions but I would like to know every option so I can make a good choice. My last question is: what do converters are, and when to use them and when they cannot be used? Thanks for all the advices you might have!