When Parker created the Vacumatic they came up with one of the greatest pens ever. The design is clean, functional, and distinctive. The filler is a small pump that uses a few pumps to fill the pen body with ink. They were first introduced in 1933 on a very small scale and the pens were marked as Golden Arrow pens. There was a problem with the name and it was changed to Vacuum-Filler in early 1933 and later in the year the name was finally changed to Vacumatic. Nibs are usually the typical Parker Arrow variety but they are also found marked Vacuum-Filler and Vacumatic. There were a number of changes as the years went on. All of the pens are good and I can see no real difference in quality over the years. They are great writers and well worth having and using on a regular basis.
There are a few bad points to the pens. The plastic is a form of Nitro Cellulose like the explosive used to fire cannons. When these pens catch on fire they burn very fast. Avoid open flames with these pens. They are also a little harder to repair than other pens. The filler requires a special tool to effectively remove or replace it. The blind caps rarely line up after the filler is repaired and care must be taken for proper fit. If the jewels need to be replaced it can be hard to find the correct one. As a bright point the pens can be restored very close to the original beauty.
Dating Vacumatics is pretty easy. Lock down fillers were used from 1933-1936. Speed line fillers are the metal ones that do not lock down were from 1937-1940. And the plastic fillers are from 1941 and later. The arrow clip that does not say Parker is 1939 and earlier. Those that say Parker are 1939 and later. Star clips are 1938-1939 or so. Better yet Parker actually put the year and quarter of manufacture on most of the pens. There is a small number at the end of the inscription and on the nib. The number in the ones column is the last digit of the date. If there are any dots next to the number then they are the quarter of the year. Three dots is the first quarter and none means the fourth. I do not know the meaning of the number that is occasionally in the tens place. A pen with a lock down filler and the number 6.. was made in the second quarter of 1936.