I was recently asked to do some research into the construction of double knit sailors caps/voyageur caps/tuques (lots of names depending on who you are and what you are representing), and this is the result. It combines information from extant caps both in Holland and in Canada, with most of the detailing in this instance being from the Machault cap, right down to the little 'ear dents' that are a feature of this cap but which rarely show up in reconstructed versions..
It starts out as a very long seamlessly knitted 'flat rugby ball' shape, which is then heavily fulled to give this result:
I'm not entirely sure yet if these will make it into my regular 'off the peg' range for the simple reason that being double caps thay take an absolute age to knit, but I think I will be writing up the pattern, with extensive notes and reference material for my range of historic patterns.
I'm pleased with it, and will be continuing the research with a reconstruction of the tie dyed indigo and white double knit Whalers Cap from the Rijksmuseum.