Abstract: Modular fountain pens useable with inks of varying viscosities that utilize a nib with exterior grooves for conveying ink, which removably fits into a coupler that places the nib in fluid communication with a reservoir by way of a central ink tube. The coupler removably secures into a housing, which is closed on its opposite end by a rotating end cap designed to engage the ink reservoir so as to allow the pen user to adjust the internal volume of the reservoir. The pen allows for quick assembly and disassembly, which allows the pen to be easily cleaned between uses to accommodate fluid inks that may leave heavy residues and also allows for the appearance of the pen to be changed according to user tastes. The use of a quick-removing nib allows for a double-tipped nib to be used, with different writing tips, and easy swapping by the pen user between writing tips.

Abstract: Modular fountain pens useable with inks of varying viscosities that utilize a nib with exterior grooves for conveying ink, which removably fits into a coupler that places the nib in fluid communication with a reservoir by way of a central ink tube. The coupler removably secures into a housing, which is closed on its opposite end by a rotating end cap designed to engage the ink reservoir so as to allow the pen user to adjust the internal volume of the reservoir. The pen allows for quick assembly and disassembly, which allows the pen to be easily cleaned between uses to accommodate fluid inks that may leave heavy residues and also allows for the appearance of the pen to be changed according to user tastes. The use of a quick-removing nib allows for a double-tipped nib to be used, with different writing tips, and easy swapping by the pen user between writing tips.