We regularly find unusual things in fountain pens. Sometimes they don’t belong. Sometimes they do. Sometimes we understand why they are there. Sometimes we don’t. Sometimes they make us shudder. Sometimes they still make us shudder long after the pen has gone home.
Behold, what we found in an innocent Esterbrook “J” pen. As you can see from the photo, the portion of the sac attached to the section’s nipple is intact and behaving like rubber ought: stretchy. The portion of the sac at the far end is likewise pliable. But the portion of the sac in the middle is different. It is a gooey mess: sticky, viscous, and disintegrating. How could this be?
We have seen this countless times before. Each time we ask the customer, and—nearly without exception—have our suspicions confirmed. They have filled the pen with a boutique ink, usually a super-saturated colour.
We realize that many pen users out there love specialty inks. They love the colours. They love the exclusivity. Sometimes these inks offer characteristics not found elsewhere (such as indelibility, colourfastness, etc.) These qualities are excellent to have, but they can come at a cost.
Boutique inks are often made in small batches, by creative souls for whom ink is a passion, and chemistry is fun. But these enterprising folks usually don’t have the resources for serious research & development. They don’t have professional chemists available. And they often don’t have a supply of disposable vintage pens available for quality analysis.
As a result, there can be inks on the market which do fine in contact with modern acrylic or resin plastics. In a cartridge-converter, they are well-behaved. But put in contact with a rubber sac for days, weeks, or months, they can have an effect like that in the photo, above. And after they compromise the sac, they then can sit in contact with vintage plastics, and also have a damaging effect.
So, we know you love your inks. And that is understandable. But we love your vintage pens. And we have seen too many examples over the years to be co-incidence: please don’t mix boutique inks and vintage pens.
What inks are safe to use in a vintage pen? Simply put, those made by the larger manufacturers: Parker, Waterman, & Pelikan are all good examples. J Herbin produces lovely colours, and has been doing so for hundreds of years with no damage to pens.
We love vintage pens, and we want to preserve those that remain, for as long as possible. But we also love the fact that they can still be used every day. But any time we use something old, there is an element of risk involved. Please help minimize this risk, by choosing to use the safest inks possible. And be sure that, in so doing, you will be able to use your pens for decades more to come.