Silicone pen sacs: testing for silicone

This video shows how to identify real silicone pen sacs. Our testing indicates that virtually every ink sac sold as silicone over the past several years is really PVC -- a material known to damage other plastics when left in prolonged contact. We were deceived ourselves, and are now in the process of contacting all our customers who bought pens from us over the years with these misdescribed sacs. Fortunately, we only installed them in a few pens. Unfortunately, they were installed in celluloid pens with outstanding original color -- vulnerable to discoloration from a conventional latex sac, yet also vulnerable to internal liquefaction should the PVC's plasticizer migrate into the adjoining celluloid. This risk may be small (we are not aware of any reports of such damage to date) but the potential consequences are too serious to ignore -- especially so in a product specifically marketed for safe long-term preservation of vintage plastic pens.

PS If you are impatient, you can skip straight to the heat testing part of the video by clicking here.

PPS If you would like to carry out tests of your own (please take all necessary precautions) and need samples of real silicone rubber for comparison, send us a self-addressed stamped envelope and we will send along a free snippet (we still have plenty of the tubing we bought for our initial testing!).