Like all 9xxx series nibs it’s osmiridium tipped. Nib charts from the 1950s list the nib as being for “general writing.” It’s a basic, middle of the road nib that’s not very exciting. This one has “Esterbook” and “9668” engraved the length of the nib, with Esterbrook on top of the nib number. It’s a nice clean design which I like.
My particular nib was in a batch of nibs I bought on eBay, I didn’t have a box but did appear to be in mint condition. The nib is a nice smooth writer that puts down a wide medium line. It helps that the nib is wider than the fines so it doesn’t dig into the paper fibers. There’s good flow and no hint of skipping. While it does have “firm” in the name it doesn’t feel as nail-like as the fine nibs. I’m becoming more accepting of medium nibs and this one has a nice feel to it.
It’s a basic nib that was probably pretty popular in its time. But it is a Master DuraCrome which were more expensive, so it isn’t a bargain basement nib these days. An eBay search finds one with a $15 BIN price. Anderson Pens lists it for $20 although it is out of stock.
It’s a nice medium nib. That’s not exactly a raving endorsement from me since I prefer fines and extra fines. Despite that it’s a nice writing nib and I may find myself inking it up in the future as medium nibs seem to be growing on me. The Esterbrook #9668 Firm Medium is a keeper.
I didn’t notice until posting the photos that I refer the the nib as a firm fine in the writing sample. I had fine on the brain. The nib is a firm medium.