Sacs and seals are fresh production. Prices listed below do not include shipping or insurance. If you wish to buy more than one of an item, quantities can be adjusted within the shopping cart before checkout.

Tools & Supplies -- Pencil Lead -- Nibs -- Other Parts -- Accessories

These traditional latex rubber sacs are all fresh production from the Pen Sac Company (the inheritors of the old White Rubber Company's ink sac operation). A sac of size "n" will slide freely into a hole n/64ths of an inch in diameter. Unless otherwise noted, all sacs are straight (i.e., not necked or tapered). Sacs are sold by the bag, $20 for five sacs, or an assortment of twelve in the most useful sizes (our choice) for $45.
NOTE: While latex rubber sacs can last for years under normal conditions, the use of certain inks can lead to rapid failure. Read more about ink selection for vintage pens here, and about sac materials and installation here. Sac cement is listed here.

Sac size Quantity (bags)
16 tapered
17½ x 2⅛ necked
20 necked
23 necked
24 necked
Assorted (12 sacs)

100% silicone sacs will outlast conventional latex sacs several times over, and are unaffected by the most reactive inks. As far as we know, these are the only genuine silicone sacs currently on the market (note the longitudinal seam lines: real silicone sacs have to be injection molded). Latex sacs can release sulfur compounds as they age, which discolor plastics such as celluloid. Where color preservation is of paramount importance, 100% silicone sacs are the best choice. Most sacs currently advertised as "silicone" are actually PVC (vinyl) -- a material not compatible with celluloid: over time, PVC leaches a plasticizer which is known to attack celluloid). These sacs are shorter than their latex equivalents (14 and 15 sacs are ~70 mm long; 17 sacs, ~85 mm; 18½ sacs, ~80 mm). Sacs are sold by the bag, $20 for a bag of five sacs. Bags of 25 sacs are $75; bags of 100 sacs are $200. Size 17 sacs are no longer available, and size 18½ sacs are running out. New supplies are likely at least a few years away due to supply chain issues.

NOTE: Silicone is much more permeable to air than latex, so pens with silicone sacs must be kept nib-up when not in use to prevent leakage. For the typical pen user, latex sacs are still the best option. More on choosing sac materials and their various pros and cons here.

Sac size Quantity (bags) (bags of 25) (bags of 100)

Parker 51 sacs for standard Aerometric models.

The PVC ("Pli-Glass") sacs that Parker used for their 51 Aerometrics are famously durable. Nonetheless, they do stain and darken, and eventually they will give out. We can now offer reproduction sacs made of the same material and as durable as the originals. Please note that these may stain when used with highly pigmented inks, and that they are not recommended for use in pens made of celluloid or cellulose acetate.
5 sacs for $15, 50 for $95, 100 for $150. ORDER

These sacs will also fit Parker 21 and 41 pens, as well as mid-size English-made Aerometric Duofolds. A more slender sac is required for Slimfolds and very early 51 Demis with filler housings that completely cover the sac except for the pressure bar opening on the side. For these pens, we recommend our PVC Snorkel sacs listed below, which can also be used as replacements in Parker metal-bodied squeeze-filler converters (converter repair video here).

For quantity discounts, put the item in the cart, adjust the quantity, then click Recalculate.

Sheaffer Snorkel sacs in PVC.

Replacing the sac of a Snorkel is especially time-consuming, as the pen first has to be opened, and then the sac carrier plug removed from the metal sac housing. Sac failure in a Snorkel can also be more consequential, as leakage into the pen's interior may not become apparent until after the metal parts have begun to corrode. For this reason many pen repair experts have come to favor synthetic sacs for Snorkel repair, either silicone or PVC. While silicone is the most resistant to chemical action, it is permeable enough that pens with silicone sacs require special handling (read more here). PVC is impermeable and extremely durable -- the PVC sacs of Parker 51 pens have a track record of lasting for decades -- and though they are not recommended for direct contact with celluloid or cellulose acetate, this is not an issue for Snorkels where they rest within a chromed brass housing. PVC Snorkel sacs are not as flexible as latex or silicone sacs, so will require the plunger to be depressed more rapidly and deliberately to fill completely.

NOTE: These sacs are suitable for Parker Slimfolds and other slender English Aerometric Duofolds, as well as early USA Parker 51 Demi Aerometrics and Parker metal-bodied squeeze-filler converters. They can also be used in metal-bodied and hard rubber lever and button-fillers.

5 sacs for $15, 100 for $150. ORDER

For quantity discounts, put the item in the cart, adjust the quantity, then click Recalculate.

Vacumatic sacs (Parker originally called them "diaphragms") come in three sizes. Confusingly, nearly all Vac-filling pens -- including most Parker Vacumatics, all Vac-filling Duofolds, and all Vac-filling 51s -- use "small" Vac sacs. Full-sized lockdown-filler Vacumatics use medium Vac sacs. Oversized lockdown-filler Vacumatics use oversize Vac sacs, though the medium sacs can be used in a pinch. More on Vac filler repair here.

Waterman Ink-Vue pens use another special sac. Standard and Deluxe Ink-Vue pens use standard-sized Ink-Vue sacs, while the little Lady Patricia Ink-Vue uses a smaller sac. Note that the late 5116 Ink-Vue with its one-piece barrel uses a completely different sac, that is not currently manufactured.

Vacumatic and Ink-Vue sacs are priced at $15 for a bag of 3.

Sac type Quantity (bags)
Vacumatic, small
Vacumatic, medium
Vacumatic, oversize
Vacumatic, one of each size
Ink-Vue, standard
Ink-Vue, small

NOTE: To order 100 of an item packaged in bags of 20, set the quantity in the cart at 5, then click Recalculate.

O-ring seals for Parker 51 Aerometric pens with a recess in the hood (shell). Do not install on pens with no seal recess in the hood! Newly manufactured to original specifications. Available in two sizes, for standard and Demi pens.
5 seals for $5, 20 for $15, 50 for $25

O-rings for Sheaffer pneumatic-fillers (these fit inside the end of the barrel, making an airtight seal with the plunger), newly manufactured to original specifications, now in long-lasting ethylene-propylene*.
20 for $12 or 100 for $45

NOTE: small rings fit Snorkels and most Touchdowns, including Imperials; large rings fit PFMs, 1949 Touchdowns (the fat first-year model), and Touchdown Tuckaways. (installation instructions here)

Point seals for Snorkel and PFM (these fit inside the nib/section assembly, sealing around the extending filler tube). Custom-made to our specifications in long-lasting ethylene-propylene*. These seals are of critical importance, for when old seals leak they may allow ink to be sucked into the pen's interior, causing the spring to rust and freeze up the mechanism: 20 for $20 or 100 for $75

* Ethylene-propylene seals should last at least twice as long as those made of ordinary rubber, which are vulnerable to oxidization, and especially the effects of ozone. Use only with pure silicone grease, keep away from petroleum-based lubricants.

Replacement ink sacs for Snorkel, Touchdown, and PFM repair are listed above. Correct sizes are as follows: #14 for Snorkels; #15 for slender Touchdowns, including Imperials; #17½ or #17 for Touchdown Tuckaways, PFMs, and fat-barreled first-year (1949) Touchdowns. Note that a half-size difference is only 1/128 inch (0.2 mm) -- not much more than the typical range of dimensional variation for dip-molded sacs.

(more on sac selection for pneumatic-fillers here)

Repair kits for Sheaffer pneumatic-fillers, $18 each. Snorkel and PFM kits each include three sacs, three point seals, and three barrel-plunger seals; Touchdown kit comprises a total of four sacs and four barrel-plunger seals, two each of each of the two sizes used. Sac lengths may differ from those shown in the illustrations above. Touchdown repair instructions may be found here; Snorkel and PFM instructions, here.

These kits are also available with silicone sacs at the same price (pros and cons of different sac materials explained here). PVC sacs are an additional option, but only for the Snorkel kit.

General-purpose piston-filler seal replacement kit. Assortment includes 40 O-ring seals, 10 in each of four different graduated sizes. Easily installed replacements for traditional cork seals, use singly or in pairs, or in combination with greased felt washers. Will fit a wide variety of vintage European piston-fillers -- we have used these on pens by Aurora, Kaweco, Montblanc, Osmia, Pelikan, Soennecken, and others. We recommend slightly roughening the outside bearing surfaces of these seals with fine sandpaper for better grease retention and reduced stiction. $25/kit


(NOTE: This is the same assortment offered for Conklin Nozac repair below)

Piston seals for Pelikan 100 and 100N. Use in pairs as replacement for original cork seals -- will not fit pistons originally made to use synthetic seals.

Durable and easy to install, use with silicone grease for smooth action. Much faster than cutting and fitting a cork seal, no worries about cork seals drying out or shrinking. We recommend slightly roughening the outside bearing surfaces of these seals with fine sandpaper for better grease retention and reduced stiction.

Seals shown above installed in a transparent acrylic replacement barrel (at left) and in an original celluloid barrel (at right).


As above, but for vintage Aurora 88 fountain pens, replace original rubber and felt washers on piston. We recommend slightly roughening the outside bearing surfaces of these seals with fine sandpaper for better grease retention and reduced stiction.


Piston seals for Pelikan 100N, 400, 120, and 140 family pens. Secure snap-fit replacements for original synthetic seals, new manufacture, shown below mounted on Pelikan piston-filling mechanisms (not included). These seals are modeled on an original Pelikan piston seal design of the early 1950s. They come in two sizes: the clear and black seals are designed for precise sealing in barrels with a 9.0 mm inner diameter; the green seals are optimized for diameters of 9.1 to 9.2 mm.

In general, the larger green seals fit earlier production Pelikan 100N series pens with celluloid barrels, while the smaller clear and black seals fit late-production 100N pens with acrylic barrels as well as the 120/140/400 series pens. Unfortunately, there is much inconsistency in Pelikan barrel size, so we recommend that you order a mix of sizes -- let us know how much of each color to send.

$10 each or 5 for $40 (please don't forget to specify the color mix desired)


Piston seals for Conklin Nozacs (use in pairs). Kit includes 40 O-ring seals, 10 in each of four different graduated sizes. Sizes A and B will fit most standard-sized (5000-word) Nozacs, use C or D for oversize pens (7000-word). O-rings stretch over the piston head, seal tighter with less friction than any other seals we've tried. No more time-consuming gluing together of split cork! May also be used for a wide range of other piston-fillers. We recommend slightly roughening the outside bearing surfaces of these seals with fine sandpaper for better grease retention and reduced stiction. $25/kit


(installation instructions here)

Packing seals for Waterman safety pens (use two or three to replace the original cork shaft seal). Will fit pens up to #5-size (Waterman 45). Newly-manufactured in fluorocarbon rubber** for maximum durability and chemical resistance.
20 seals for $15


(installation instructions here)

Packing gaskets for plunger-fillers, replace original innards of Sheaffer, Eversharp, and Conklin packing units. Newly-manufactured in fluorocarbon rubber** for maximum durability and chemical resistance. New improved design is two seals in one, with raised lips both inside and out for less friction, more flexibility, and better lubricant retention. These seal against the shaft -- not to be confused with the washer-shaped piston seals attached to the end of the plunger. For best results, seat the closure washer all the way into the packing unit compartment so that the gasket is held firmly in place with no wiggle room (closure washers will have to have their outside diameter slightly reduced to fit).

10 gaskets for $15 or 100 for $65


(installation instructions here)

** Fluorocarbon seals are extremely durable, resisting wear & weathering far better than standard synthetic rubber seals (estimated lifespan in industrial settings is up to 20 years, versus 2 to 5 years for the standard synthetic rubber, butadiene).

Our original plunger-filler packing unit seals are also still available. These are simple fluorocarbon rubber O-rings, a popular design that is time-tested and easy to install.

20 gaskets for $12 or 100 for $25


Precision-cut styrene closure washers to complete plunger-filler gasket installation, used to reclose the packing unit. Custom-made to our specifications: 20 for $8 or 100 for $25


Plunger-filler packing unit rebuild kit, includes ten each of the above-listed seals and closure washers, plus a long-necked solvent applicator: $18


Long-necked multipurpose applicator, perfect for applying solvent cement in plunger-filler repair, and a superior filler for eyedropper-filling pens (the long, thin tube reaches further into the barrel, filling it more neatly). The tube is thin enough to insert into converters, allowing them to be flushed out easily and conveniently:
$0.50 each, ten for $2.50


Sheet stock for plunger-filler piston washer seals, top-grade synthetic rubber, proper stiffness and thickness for optimal filling and long service. This is not an off-the-shelf product: the nonstandard thickness is the same used for original Sheaffer piston seals. Equally suitable for Eversharp and Conklin plunger-fillers of the same era.

High grade industrial felt, 1/16" (1.6 mm) thick; 95% wool, tough and dense, used in packing units and in some piston seals, layered with rubber washers, the felt serving to absorb and retain the silicone grease that seals and lubricates the seal assembly. Not to be confused with fabric and craft store felt, which is thin and flimsy and insufficiently absorbent.
$4 for a 4" x 6" (10 x 15 cm) sheet.


For quantity discounts, put the item in the cart, adjust the quantity, then click Recalculate.