Hi all, I was going to order a Faber-Castell Loom and I was wondering if anyone knew if a standard international cartridge would work with it? One review mentioned that they couldn't fit one in there but everything I can find says the it takes international cartridge. Is there some other reason that an international cc wouldn't fit in this pen? If so, are there any other options? I know I could refill cartridges but I would really prefer to use some sort of filling mechanism. Thanks!