Thank you for your interest in our office products and, specifically, the awesome gel pens! I'd be happy to answer that question for you.
The G2 Roller Ball Retractable Gel Pen is a pen that has ink supplied through a refill, therefore you should not have a problem with the pen leaking while you are traveling, regardless of the cabin pressure.
I would recommend carrying your liquid pens in a ziploc bag when you are traveling on an airplane because there is a higher tendency for those pens to leak. But the gel pens, especially the G2 pens, you shouldn't have a problem with.
We really appreciate your business and look forward to working with you on your next order of office supplies. Please let us know if you have any other questions about our office products.
Remember, we offer over 40,000 products online that are available to ship nationwide. Most orders arrive the next day and most orders over $75 have no shipping charge! We look forward to making you a satisfied customer!
The On Time Supplies Team