The best demonstrator fountain pens

A piston filler holds far more ink than a cartridge and costs nothing to refill after the first bottle. That combination usually starts at three times this price, which is why the ECO turns up on every beginner list that takes bottled ink seriously.

The clear barrel is not just decoration. You can see how much ink is left, which removes the most common beginner surprise: a pen that stops mid-sentence with no warning.

TWSBI's own guidance on choosing a nib is unusually plain: extra fine if you write small, fine for a normal hand, medium if you write large, broad for headings and signatures.

The GO strips the ECO down to its cheapest honest form: no piston mechanism, just a spring and a plunger, and a barrel you fill straight from a bottle.

It holds a lot of ink for the price and shows you exactly how much is left. For someone who has decided they want bottled ink and does not want to spend more than the ink costs, this is the shortest route.

The shape is divisive and the build is plainly economical. It is a tool, not an object.

Platinum publishes the nib width in millimeters, which almost nobody else in this category does. That single fact makes the Preppy the cleanest reference point on the whole site: when we say a Japanese Fine is about 0.3 mm, this is the pen we can point at.

The slip-and-seal cap is the other reason it matters. Platinum's cap mechanism keeps the nib from drying out for months, so a Preppy left in a drawer usually writes on the first stroke — the failure that puts most beginners off fountain pens for good.

It is still a cheap plastic pen. The cap cracks if you post it hard, and the body is not built to survive a bag full of keys.

A demonstrator body is a teaching tool disguised as a style choice. You can watch the converter draw ink, see the feed's channels fill, and know exactly how much ink is left — three things that are otherwise invisible and mysterious.

It is the same pen as the Safari in every other respect, so everything true of that pen is true here.

Clear plastic shows ink staining. Some inks will tint the section permanently, which bothers some people a great deal and others not at all.

The listing publishes the figures that matter for a pen this cheap: a steel Fine nib, 135 mm capped, 16.5 g, and a screw converter in the box. A converter at this price is the whole argument — you can fill it from a bottle on day one instead of hunting for proprietary cartridges.

Sixteen and a half grams is light. That is a plastic pen and it feels like one, which for long sessions is an advantage rather than a complaint.

Jinhao does not state the Fine nib's width in millimeters, so we do not publish one. In practice Chinese Fine tends to sit between a Japanese Fine and a European Fine, and the nib size guide explains why that sentence has to be that vague.

This is the cheapest way to find out whether you like a piston filler. The mechanism is built into the barrel, so there is no converter to buy and the ink capacity is larger than a cartridge pen's — the same argument the TWSBI ECO makes at four times the money.

Buying four pens at once sounds like a gimmick and is actually the point: you can ink four different colors, or keep one filled and three spare, or accept that at this price one of them may be a dud.

The seller lists the nib as iridium extra fine but publishes no width in millimeters, so we do not print one.