This page refers to the Balance model using this name.
The Junior is essentially a Craftsman foreshortened— except for some very late examples, because Sheaffer began to offer a “long model” in 1939 or ’40 that was the same length as the Craftsman. It was just about the lowest priced pen in the catalogues of the day, although as was so often the case it is difficult to see just where the savings are being had; evidently it’s in the plating, which is not gold, but (probably) nickel. The points of Juniors will have the model name on them if they’re original to the pen, and the clip is marked “Sheaffer Jr.”
Production Run: c. 1934 (it appears in a ’34 brochure, but not in the ’30 catalogue) – 1942 (this line did not survive into the Triumph era).
Cost When New: $2.75 (for modern value, try this calculator).
Size: Flat-end version: 11.3 cm long capped, 14.0 cm poster, 9.8 cm uncapped. Tapered version: 12.0cm long capped, 14.0 cm posted, 10.5 cm uncapped.
Point: 14k gold.
Body: Celluloid.
Filler: Lever, capacity approx. 0.8 ml or vacuum filler, capacity approx. 1.3 ml. So far as I can discover, the early version only appeared as a lever-filler
Sheaffer Junior of the earlier sort.
Sheaffer Junior, grey pearl striated. This is a “window pane” version of the vacuum filler
Sheaffer Junior lever-filler, ebonized pearl. This colour was removed from the line-up in 1939
Sheaffer Junior lever version, marine green striated
Sheaffer Junior in Rose Glow which was available from 1936 to 1939 (not to scale with other portraits)
If you are relying on the preceding information to win a bet or impress a teacher, you should read the site’s scholarly caveat. Remember, this is the internet, and it’s full of bad information.