Without doubt, Esterbrook's most popular and best selling pens were in the J series.  While most people think of J pens being double jewel models from 1948 on, they in fact first appear in the 1941 catalog as part of the very short lived series called Visumasters.  These pens are immediately distinguishable from other Esterbrook pens by the alternating thin and wide strips of marbled plastic, the very clear visulated section (ypically does not amber like other brands), and metal jewel with the Esterbrook name between cross hatched lines.  These pens often came with a unique 9xxx series nib that has a frosted grey section on them, often with reference to being "Osmiridium Tipped."

There are three main variants of Visumasters (actually, I've noted a fourth variant, but it is a slight imprint variant).  This is what I refer to as a Visumaster 1.  Note the tapered barrel end that distinguishes this from other variants.  This unfortunately results in a poorly posting pen.  Also note the stepped barrel design below the threads.  This Model has the metal jewel on the cap and a longer than normal cap.  Traditional later J model caps will not fit on this pen due to the elongated visulated section.  There is also a second variant of this pen with a slightly different imprint.  The pencil is called the Pushmaster.

The red Visumaster is one of the most vibrant colors made as can be seen on this model.  The Blue model is often smokey blue in color compared to other Blue J pens.

This is what I refer to as a Visumaster 2.  Note the more standard barrel, with less of a taper to the end.  There is no step below the threads.  This pen also has the metal jewel and visulated section.

When is a Visumaster not a visulated pen?  With what I refer to as a Visumaster 3, the standard black section comes into play, and the pen loses it's metal jewel in lieu of the three ribbed black plastic jewel.  This variant has a shorter cap that will not fit on a Vis 1 or 2 and is more in line with the later J series in length.

These are hard to find Twist Fillers ca. 1943. These have 8xxx series nibs in palladium silver which were produced for a short time during the war years. These pens sold for $3.50 but when introduced, stores still had inventory of previous lever filler models at the cheaper $1.00 price so these did not sell well, and, consequently, are very hard to find.  These maintain the three ribbed jewel from the Vis 3 above.  These were produced in the standard six colors.

It's a bird, it's a plane, it's, well, what the heck IS this? It's truly a transitional model, but on the early side of things, with the metal jeweled tapered cap and J style clip but bandless style cap bands. Not something you see very often.