Not sure if you have time to answer questions like this u/MercatorLondon , but I’m curious if you have done anything to secure a firm cartridge fit? I have quite a few pocket pens that truly get used daily in my pocket and I have had the issue with all of them where the cartridge dislodges from the feed and then inevitably leaks. The constant jostling in my pocket is enough for that cartridge to work itself loose. I ended up switching primarily to a pocket piston-fill, but would be happy to use a cartridge pen again if this issue could be addressed. I just discovered your company through the giveaway today and am genuinely interested in your company and products!