I was browsing one day and made the mistake of checking out the pilot 823. The result is that now I want one.

But then I had another look at the thing and thought, "Hey, if I have to pull the piston up before filling, does that mean I can't change colours before emptying the pen?"

I mean where would the ink in the barrel go? Out the back?

p.s. Is this the dumbest question asked here ever?

As far as I know like every self filling pen to change colour in your pen first you must dump out the old ink in your pen then rinse it with water and then fill it with the new ink.
The C/C main advantage over self filling pens is its ability to chance cartriges with different colours.

I would assume the ink is forced out the front of the pen, ie the same way as the ink went in.

Hi,

When you pull the plunger back, ink rushes past the plunger, then when you push the plunger down, the plunger forces anything (air, ink, water) that was in front of it out, creating a vacuum behind the plunger. This vacuum is released when the plunger reaches the bottom of the barrel, and ink rushes into the pen to fill the vacuum.

To answer your question more pointedly, the ink goes from behind the plunger to the front of the plunger when you are pulling it back, so it stays in the pen the whole time.

Dillon

So there some kind of valve on the plunger such that things can flow through it on the way up but not on the way down?

Clever!

I have the Pilot Custom 823 and, yes, that pretty much describes what happens. Ink in the barrel is expelled on the down stroke and if the pen is submerged in ink, it also allows ink to enter the barrel on the down stroke. Nothing significant goes in or out of the pen on the up stroke.

It's the same basic idea as the Sheaffer Vac-Fil or the Parker Vacumatic. Richard's Pens has a pretty good article explaining how they work, if you are interested in knowing more.