TWSBI VAC 700 Fountain Pen Review

The TWSBI Vac 700 ‘s introduction a few years ago was met with both excitement and frustration. I remember Fountain Pen Network being extremely excited by the prospect of a value priced vacuum filler, but the initial release had problems with the nib and feed resulting in many Vac 700s writing extremely dry. The clear demonstrator Vac 700 was delayed for several months while TWSBI worked out the kinks. I finally got around to purchasing the Vac 700 after the major price drop last year.

TWSBI Vac 700

The Vac 700 boasts a vacuum filler system and a monstrous ink capacity of 1.5 ml. The pen is available in clear, smoke, sapphire, and amber plastics with black accents. The nibs are German made nibs from JoWo and are available from Western EF up to 1.5mm stub. The nib size is a standard #6.

Capped, the TWSBI Vac 700 is 14.8 cm long. Uncapped, the pen is 13.4 cm long. The section is made from black plastic and is 1.1 cm wide. The barrel has a bit of a taper that flares out just before the section. The cap sits almost flush to the flare, protruding just a bit. The barrel is perfectly smooth, which provides for a clear unimpeded view of the vacuum filling system, but also can roll off the desk. As usual, TWSBI includes a wrench and some silicone oil for user servicing.

The Vac 700 is not the best pen to post, as it posts rather shallow and the heavy cap throws the pen way off balance. The grip feels great in my hands and the threads aren ‘t too sharp. I really wish TWSBI made a Vac 700 that used only clear plastics like the Diamond series of pens, but the classy look of the black and smoke plastics have slowly grown on me.

TWSBI Vac 700 with Vac 20 Ink Bottle

The vacuum filling system is one of the less common filling systems in the fountain pen world. It ‘s not so rare that only a few pens use it, but there are a lot more piston fillers and C/C pens out there. The end cap is unscrewed to open a valve that allows flow from the barrel into the feed. To fill the Vac 700, the end cap is unscrewed completely, then the cap is pulled back to draw the metal plunger all the way to the back of the pen.  The Vac 700 is then placed into a bottle of ink and the plunger is pushed down. The plunger pushes all the air into the bottle of ink, creating a vacuum in the barrel of the pen. The ink shoots up into the barrel to equalize the pressure. With a regular ink bottle, the Vac 700 can be filled about 2/3 to 3/4 way full. To get a full fill, the user will need to either pull the pen out of the ink, point the nib upwards, pull out the plunger again, then carefully push the plunger down to expel any remaining air from the pen. Finally, the pen is placed back into the bottle of the ink and the plunger is pushed the remaining way down. This method can be messy for the physically uncoordinated (like me) as there is a risk the plunger may be accidentally pushed all the way down when expelling air. The other alternative is to purchase a TWSBI Vac 20 ink bottle. The Vac 20 bottle is a small plastic bottle with two screw on lids. The upper stopper can be unscrewed, allowing the Vac 700 to be screwed directly into the bottle. The bottle and pen is then turned upside down and the Vac 700 plunger is operated from this position for a full fill with the first plunge.

Personally I find the vacuum filling mechanism to be loads of fun. The Vac 20 bottle helps quite a bit as I find expelling air from the pen tends to cause little bubbles of ink to fly out of the pen. Since the plunger can be screwed all the way down, sealing barrel from the feed, the Vac 700 is an ideal pen for frequent fliers who don ‘t want to be without a fountain pen. The seal means no matter what changes in air pressure occurs, bubbles of ink will not be forced out through the nib. It is possible to do a few paragraphs of writing with the barrel sealed, but eventually the end cap will need to be turned until a slight pop is felt to saturate the feed with more ink. I noticed that its best to leave the pen valve unsealed if you ‘re a very occasional writer, as it prevents the feed from drying out and causing skips and stoppages.

TWSBI outfits its pens (save for a few early Diamond 530s and 540s) with JoWo nibs. I purchased mine with an extra fine nib. I found that out of the box it struck a great balance for wetness and was very smooth. I did not feel any need to do any tuning or smoothing. Early batches Vac 700s had issues with being exceptionally dry to the point of skipping constantly. TWSBI delayed the clear Vac 700 ‘s release to sort out these issues, and I can say for certain my pen does not experience any of these symptoms.

TWSBI Vac 700 EF Nib

The Vac 700 uses a standard #6 nib size. In theory, the feed should accept any old #6 nibs. I ‘ve had great success fitting Knox brand nibs into my Diamond 540, but I have not had the same result with the Vac 700. I attempted to fit a 1.1mm stub nib from Knox in the Vac 700 and had some serious flow issues. It appears that the nib and the feed simply did not fit well together. Unless you enjoy tinkering with pens, I would recommend sticking with the official TWSBI Vac 700 nib units in this instance.

The original asking price for the Vac 700 was a little much for my taste. But after the pen was dropped down to $65 USD, I felt the pen was a fabulous value. The Vac 700 continues TWSBIs tradition of high value pens. It ‘s a great choice for someone looking for an affordable vacuum filler with monstrous ink capacity and those concerned about their pens during air travel. Fellow university students who are constantly worried if they ‘ll have enough ink in the tank should seriously look into this pen. Those who must post their pens might want to wait for the eventual release of the Vac Mini. If the TWSBI Mini is any indication, it will be an easily posted pocket pen at the expense of ink capacity.

TWSBI Vac 700 Review Recap

TWSBI Vac 700 Extra Fine
Ink: Sailor Jentle Sky High   Paper: Clairefontaine 90g

+ Can be serviced by the user
+ Comes with tools and silicone oil
+ Smooth nib out of the box
+ Vacuum filler system at a value price
+ Nib units easily swapped

– Doesn ‘t come in full clear plastic
– Too heavy to post
– Round body can roll off desks
– Tricky to get a full fill without the Vac 20 ink bottle


Thanks to steveH for catching my error. I originally stated the nibs were from Bock, not JoWo.

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