AJ-lamp cable  

Link below for braided flex...
Link below for braided flex - not sure if its right for an AJ though as its more typically a 30s/40s style. You can also get a more lightweight version of the braided type you might see on an clothes iron etc, but you have to remember that modern electrical regulations means that flex is often more robust and hence thicker than might have been used originally. For a 'modern' lamp like an AJ I would probably just choose 0.5 width 3 core black plastic which is fairly unobtrusive.
http://www.lampsandlights.co.uk/flex3.htm

Thanks for anwser . . .
. . . and for the link. I haven't seen this kind of cables - they were great! However, these are braided and twisted separately. I am thinking of the kind of cable which you can see on a new Artichoke lamp from Louis Poulsen.

here is a pic . . .
on the kind of cable sitting on a new Artichoke lamp:
http://www.flickr.com/photos/24648757@N04/2330989753/

yeah I know the sort (its...
yeah I know the sort (its what I meant by lightweight version of the sort used on irons). I've used it a couple of times for rewiring German Bauhaus lamps etc - Christopher Wray Lighting in London have it in 3 or 4 colours - unfortunately they don't show accesories on their website anymore but you could try calling them - I don't know where you are but shipping shouldn't cost much wherever.
http://www.christopherwray.com

Thanks
for your kind and informative answer. I am in Europe, close to Stockholm.