Writing instruments

A writing instrument comprising:

• a barrel having a longitudinal axis,
• a cartridge,
• a writing tip provided at one end of the cartridge,
• a self-retracting and sealing system configured to slide the cartridge axially inside the barrel between a first extended forward position wherein the writing tip extends outside the barrel and a second retracted rearward position wherein the writing tip is retracted inside the barrel from the first extended forward position along an axial rearward direction, the self-retracting and sealing system comprising:
• a button configured to, when actuated, move the cartridge into the first extended forward position, and when not actuated, move the cartridge into the second retracted rearward position, and
• a sealing member configured to be actuated between a closed position where the sealing member substantially closes a writing passage of the writing instrument and an open position where the writing passage is not closed by the sealing member, wherein
• the cartridge is configured to actuate the sealing member from the closed position to the open position when the cartridge is moved from the second retracted rearward position to the first extended forward position and to allow the sealing member to move from the open position to the closed position when the cartridge is in the second retracted rearward position.