“A normal fiber tip pen with water-based ink and good air tightness (in the construction of the barrel and the cap fits very good), normally has a shelf life of, say, three years. Normally, you get this result [when the] temperature is 68 to 77 Fahrenheit degrees. If you store it at, let’s say, 86 Fahrenheit, you will get only, let’s say, two years. Because it’s water,” said Lugert, who noted that Faber-Castell does lab testing on its pens to determine longevity in a number of conditions.
