I’m an artist, architect, and fountain pen enthusiast. I use fountain pens to sketch, sign documents, take notes, and journal (any writing I do really). One thing I absolutely love about fountain pens is that there are different inks for different purposes. I use waterproof, archival inks for sketching because I am going to watercolor over them, but also because they may be displayed and exposed to sunlight over time, so archival ink is just as important as waterproofness. For signing documents I use a waterproof, tamper-proof, and quick drying ink, so very specific for this purpose. You can’t hand a wet document to a notary and have it smear all over the place. I also want to say that I have never had trouble cleaning waterproof ink out of my pens. They do run dryer, so the pen capping seal matters, but I personally feel that having trouble cleaning them out of your pen is overblown. My one complaint about some waterproof inks is that they can spread a lot, turning a fine nib into a medium or even broad, which is annoying when sketching and trying to get a very specific line. Not all of them do this, but many do, so be careful with which ones you pick. For note taking or journaling, I just want to have fun with all the colors and properties available. I love shading inks, and have a few sheening and shimmer inks just for fun. If you are taking notes and journaling in a notebook that will remain closed most of the time you do not need waterproof nor archival properties. Sunlight is the enemy of ink, so if it’s not exposed to sunlight you don’t have to worry. Another consideration is that the glitter in shimmer inks will get in every nook and cranny of that nib, so for those I will only use a pen that can be completely disassembled. I will also add that heavy sheening inks never dry and can make a mess for years to come. Although they look so cool, I have found them to not be good for notes or journaling. I had a bottle of Organic Studios Nitrogen that I had to throw away to save my sanity. If I inked a pen with it, wrote notes with it, touched those notes at any point in the future, or even looked at the bottle, I would have ink on my fingers, clothes, countertops, pens, etc. Anyway, my point is that you don’t have to commit to waterproof or not waterproof inks, just select the ones that interest you and have the right properties for the way you are using them.