SPR3 - PR3 - Green Ink Medium Point Space Pen Pressurized Refill

I'm a high school mathematics teacher &, since I prefer to use green ink when grading papers (I just like green...no other reason!), I bought four of the green ink refills when I bougth my Space Pen. (I purchased a matte black X-750, which has been very impressive so far; highly recommended!) I've been using the pen fitted with a green ink cartridge extensively--today I did about 6 consecutive hours of grading lengthy midterm exams (no multiple choice questions here) &, in short, I'm really impressed: the ink is delivered in a very smooth fashion & I haven't had any gaps or places where I've had to stop & get the ink running again--so the ink cartridges work exactly as advertised so far! Now, I do like the green ink, but it's a fairly subdued green, kind of like a dark, dusky forest green; it isn't quite as bright a green as I had hoped, but it's still nice and offers sufficient contrast for my paper-grading purposes. (Also, I did write briefly with the black ink before inserting a green cartridge in place of the black one that came with the pen; it looked great!) In short, I like the green ink cartridges and will happily buy them again--if I ever need to! I'm given to understand that they last quite a long time, so I'll come back again when this first cartridge finally runs out. Great product!