Platinum's nib-width digits: only three of them have ever been confirmed

Platinum fountain pens end with two numbers: colour first, nib width second. Like Sailor, the width is meant to be readable from a digit.

Except that nobody has finished reading it.

Only three digits have been confirmed

Cross-referencing every Platinum fountain pen on record, exactly three width digits map cleanly:

• 2 — fine
• 3 — medium
• 4 — broad

Those are settled. The problem is everything else. Pens numbered 0, 1, 5, 6 and 9 genuinely exist, but no published source confirms which width each one denotes.

The digits are known. Their meaning is not. Where Sailor's system has been solved down to six digits, Platinum stops at three.

The colour digit does not travel between series

The colour half has no cross-series table either. The same number denotes different colours in different lines — the same situation as Sailor.

Preppy is built differently

Platinum has one further exception. The Preppy alone uses two different number formats at once: one that joins colour and width with a hyphen, and one that simply runs the digits together. Both exist.

It is a budget pen that has sold for a very long time, so it is easy to imagine the notation changed at some point. That is a guess, and it is written here as one.

What is unknown is recorded as unknown

PencilDB marks any width digit whose meaning has not been confirmed as unverified. Nothing gets a plausible-looking guess filled in.

If you own a Platinum and know what one of those digits actually corresponds to, you can propose a correction from that pen's page. A single confirmation carries over to every other pen using the same digit.

(Compiled from the Platinum fountain pens recorded in PencilDB, August 2026.)