The perfect companion to your Rite in the Rain notepad, the permanent ink writes through water, grease and mud without clumping or smearing and at any angle. The ink and delivery system used exclusively in Rite in the Rain refills will write without skipping in extremely wet conditions far better than other comparable weatherproof pens. Tiny pockets in the pen's tip will deliver ink in the worst conditions without allowing water or air back into the cartridge.