Having just - again - rushed to the dry-cleaners with a £300 jacket, would someone please tell me if there is a good washable fountain pen ink?

I do believe Waterman's Florida Blue is washable ("effacable"). It is also an excellent ink.

Florida Blue and Blue-Black from Waterman both tend to go out the door with water.

In fact I had a pen uncap in a shirt pocket and bleed all over it at one point last summer. I believe it had Florida Blue in it. I washed the shirt in the regular cycle washing machine that night and it came out 100%- no lasting stain.

It has been my experience that many (not all) FP inks from the larger manufacturers (ie. not Noodler's , PR, etc.) can be largely or entirely removed from fabrics with prolonged soaking in room temp water, to which a goodly amount of household ammonia has been added. Gentle brushing with an old toothbrush will help. Obviously, test an inconspicuous part of the garment for any unfavorable reaction to ammonia. For ball point ink stains use household alcohol instead. (Remember to avoid alcohol contacting fountain pens; it will likely react badly on the interior plastic.....errr ..Lord help us, precious resins.)

I've asked a few people in the know about the best ink to use in a demonstrator and the answer seems to be always Skrip Washeable Blue, the original which is always for sale on E bay somewhere.
cheers
skyp

The best are all inks denoted as washable blue, which is available from Parker, Waterman, Lamy and Pelikan as far as I am aware. They don't leave a trace at all after washing.

Next up are normal, non-permanent bluish inks, IOW blue, blue black, and turqoisy inks. Examples: Waterman Blue Black, Waterman South Seas Blue, Waterman Florida Blue (although that may well be a washable blue anyway), and similar Parker inks. These inks may leave a faint trace, but IME they come out completely.

HTH, warm regards, Wim

PR American Blue is a vivid beautiful blue that in my experience washes out readily and completely in water.

x2 on this. Most of my ink stains end up on work shirts which end up at the cleaners, and the cleaners never have any trouble removing the stain. I've found this to be the case with PR American Blue, DC Supershow Blue, Electric DC Supershow Blue, Midnight Blues, and possibly more (can't say for sure).

Certainly stay away from Aurora Black if this is a concern. I permanently ruined a carpet this way.

Diamine now also makes a washable blue

In the Parker Quink range, there is also a "washable black" listed in the Ink Reviews index, although there are no reviews yet. There is a review of Parker Quink washable blue, and also a washable purple in old stock Sheaffer Skrip although you might have trouble finding the ink.

Regards, Myles.

almost any European Royal Blue or Blue ink, if it has washable/effaçable/the word in any other language meaning washable or erasable then it is definatly washable. J.Herbin advertizes Bleu Myosotis as such.

Sheaffer Skrip Blue from Slovenia is also very washable in my experience.

Amodex Ink and Stain Remover has worked very well for me against fabric stains from fountain pen inks that are not advertised as "washable." It is made in the USA and sold at many online and bricks & mortar pen shops here, and now it is available from The Writing Desk desk in the UK at the bottom of this linked page (I'm just a satisfied customer of TWD).