[quote name='louisthebass' timestamp='1424702562' post='2699329']
I think on Carol Kaye's website she favours playing triplets with a downstroke, followed by two upstrokes?
[/quote]
Can't imagine how difficult that would be!
I started bass after playing guitar, so im pretty proficient with a plectrum.
Down-up-down is the method i use.
But your hand should constantly be moving. Its quite hard to explain this in writing, but basically you play "down - up -down - up", but on the second "up", retract the plectrum so it doesnt play the note.
I dont know if this is obvious, but people i have shown, always try to reset the picking hand, rather than keep a constant motion and just exclude playing the 4th note.
Hope that makes sense to you