Join the growing community of curious minds on IDNLearn.com and get the answers you need. Discover prompt and accurate answers from our experts, ensuring you get the information you need quickly.
Answer: A piston-filling fountain pen has a piston — just like in a car — inside the barrel. This piston goes down to expel air or ink and then back up, pulling ink into the barrel. The typical process is very simple, assuming the pen is clean and dry: Push the piston down, expelling any air in the barrel