

I also dislike silicone sacs they will not leak ink, but they are gas permeable and will allow air to pass into them such that the pen will leak ink through the nib and feed if it is stored horizontally or nib downward. Do not use PVC sacs, which will bond themselves chemically to the barrel wall of many pens. Replacement button and J bars can easily reduce the size of the sac by two sizes.ĭespite the fact that latex sacs do not last forever and will need to be replaced, I still recommend them as the best available alternative. You then must take into consideration the available clearence in the pen barrel. this would be the largest sac size possible for your pen. Next conver the decimal size to the nearest 64th. Measure the diameter of the section nipple where the sac attaches with callipers.

If you do not see your pen listed in the chart, you can always measure to establish sac size. For pens not listed, choose a sac that drops freely into the barrel with the pressure bar in place. In most cases, the smaller sac size vitiates the need for a necked sac unless otherwise specified, all sacs listed here are straight sacs.


This causes any air in the sac to expand, increasing the pen’s flow unpredictably and possibly causing the pen to blot, especially when it is nearly empty.įor these reasons, the charts recommend sacs that are usually one or two sizes smaller than the sizes originally used but in some cases, the difference can be as great as four sizes.
