This page will show a number of different imprints to be found on Esterbrook pens and is by no means complete. Like other brands, there are many different variations out there.
This is from an English made Relief 66.
This is a common early imprint that can be found on all hard rubber pens, $1.50 pens with two hole clips, and some plastic $1.50 style V clips. The main identifier here is the "squiggle" between the name and "Made in U.S.A."
V clips can be found with three different imprints. You'll find this and the one below on plastic pens only.
This is the third V clip variation, note the omission of the "R" and "+Co." in the imprint.
These two imprints represent the two main variants seen with all plastic dollar pens. The top variant appears to be an earlier derivation of the two and can be found on both 1934 and 1938 style clips. The bottom variant, however, is primarily found on 1938 and later clipped pens.
This imprint can be found on transitional single jewel J series pens as well as early double jewel pens without the ® symbol.
These are three different styles of Imprints found on the Renew-point Demonstrator Desk Pens.