Sacs sizes are given as the diameter measured in n/64ths of an inch. Sizing a pen involves measurement of the sac nipple on the section in n/64ths of an inch. This is a starting point, judge sac size based on how it slides in the barrel.
We will be attending the DC Pen Show (not as a vendor) and will be away from the site from August 2nd to August 7th. Any orders placed will be shipped out following our return from the show.