Pendemonium is a full time online writing equipment shop owned by Sam and Frank Fiorella

Pen Sacs - Pendemonium!

Updated January 21, 2018

Updates - **Scroll down to see our latest updates**

We carry most sizes of pen sacs and diaphragms. If you are unsure as to what size sac to order, feel free to email us for assistance. Pen sac diameters are measured in 64ths of an inch. For example, a #14 size pen sac is 14/64 inch. All straight sacs are made long and can be easily trimmed with scissors to proper length. All pen sacs sold by Pendemonium are made exclusively by The Pen Sac Company.

Not Sure of Which Sac - Click Here To View Our Sac Charts



10 of the most popular sizes includes:
1 each of #14, #20
2 each of #15, #16, #17, #18


Please order by sac size number

Pen Sac 10

#SAC-10 $2

Pen Sac 10, set of 10

#SAC-10-10 $18

Pen Sac 12

#SAC-12 $2


Pen Sac 12, set of 10

#SAC-12-10 $18


Pen Sac 14

#SAC-14 $2


Pen Sac 14, set of 10

#SAC-14-10 $18


Pen Sac 15

#SAC-15 $2


Pen Sac 15, set of 10

#SAC-15-10 $18

Pen Sac 16

#SAC-16 $2

Pen Sac 16, set of 10

#SAC-16-10 $18

Pen Sac 16T

#SAC-16T $2


10 Pen Sac 16T, set of 10

#SAC-16T-10    $18


Pen Sac 17

#SAC-17 $2

Pen Sac 17, set of 10

#SAC-17-10 $18

Pen Sac 17-1/2N

#SAC-17-1/2N $2


Pen Sac 17-1/2N, set of 10

#SAC-17-1/2N-10 $18

(Sorry, temporarily out of stock)

Pen Sac 18

#SAC-18 $2


Pen Sac 18, set of 10

#SAC-18-10 $18


Pen Sac 19

#SAC-19 $2


Pen Sac 19, set of 10

#SAC-19-10 $18

Pen Sac 20

#SAC-20 $2


Pen Sac 20, set of 10

#SAC-20-10 $18


Pen Sac 21N

#SAC-21N $2


Pen Sac 21N, set

#SAC-21N-10 $18


Pen Sac 22

#SAC-22 $2


Pen Sac 22, set of 10

#SAC-22-10 $18


Pen Sac 23N

#SAC-23N $2


Pen Sac 23N, set of 10

#SAC-23N-10 $18


Diaphragms for Parker Vacumatics and 51s

Standard Diaphragm


Standard Diaphragm, set of 10

#DIA-STD-10 $27

Debutante Diaphragm


Debutante Diaphragm, set of 1

#DIA-DEB-10 $27

Oversize Diaphragm

#DIA-OS $3


Oversize Diaphragm, set of 10

#DIA-OS-10 $27

(Sorry, temporarily out of stock)

Sacs for Waterman Ink Vue Pens

Full Size Ink Vue Sac

#IV-FS $3

Full Size Ink Vue Sac, set of 10

#IV-FS-10 $27

Lady Patricia Ink Vue Sac

#IV-LP $3

Lady Patricia Ink Vue Sac, set of 10

#IV-LP-10 $27

Pli-Glass Sacs for Parker 51 Aerometric Pens

Pli-Glass sacs for Parker 51 Aerometric fountain pens. These newly made sacs are exact reproductions of the original long lasting, super durable Parker Pli-Glass sacs. These may stain with highly pigmented inks, just like the old Pli-Glass sacs.

Not recommended for celluloid pens.


Pli-glass Ink Sac

#SAC-16-PG $3


Pli-glass Ink Sac, set of 10

#SAC-16-PG-10 $27


Sheaffer Pen Repair Kits

We've put together three repair kits for the Sheaffer PFM, Snorkel and Touchdown fountain pens.  The kits include everything you need to restore three of each of these pens.  We're also including detailed instructions on restoration excerpted from Frank Dubiel's book, Complete Guide to Fountain Pen Repair and Restoration.

Save a little cash when you buy these kits instead of purchasing the components individually!

#KIT-PFM $14

Includes 3 #17 latex Pen Sacs, 3 Large O-rings, 3 Large Point Seals and instructions for repairing a Sheaffer PFM fountain pen. 


Includes 3 #14 latex Pen Sacs, 3 Small O-rings, 3 Small Point Seals and instructions for repairing a Sheaffer Snorkel fountain pen.

#KIT-TD $8

Includes 3 #15 Pen Sacs, 3 Small O-rings and instructions for repairing a Sheaffer T.M. Touchdown fountain pen.



Based on an original Parker design. If you have fumbly fingers, a sac spreader can make installing a sac much easier!

Pen Sacs - Other Uses!

Aside from using pen sacs as their intended purpose, they have a few other useful alternative purposes as well! Use a rubber sac to oxidize your sterling silver pens in recessed areas, the Parker 75 sterling cisele pen is a good example. The rubber sac and the gas it produces is a slow way to oxidize sterling silver. This is much easier and controllable than getting the pen completely black with liver of sulfur solution.

A #22 sac is a snug fit, but can be worked on around the cap and/or barrel of a 75 FP or RB, easy fit for BP or MP. The #23 1/2N sac slides over the FP & RB easiest, BUT, the neck of the sac has to be trimmed off first so it will fit. The 22 sacs are about 3 inches long, so one on each end of pen fits over FP, RB, BP or MP. The 23 1/2N when cut is only 2.25 inches, so it would take 3 of them to completely cover any instrument, the one in the center would need to be cut open at both ends. While totally non-pen related, the smaller sized sacs, usually #10, #12 and #14 are used by model airplane enthusiasts for fuel tanks!


Site Maintained by J-TEC and Hosted by Sitevision