This enormous 1770s cap was lovingly nicknamed "the Mrs Miggins cap" by my husband. The name sort of stuck. :)
These pictures were my inspiration, but I changed and combined, as usual. I am just no good at exact reproductions. :)
more pictures of 18th century caps: https://www.pinterest.com/hertzwerk/18th-c-caps/
I used white or off white (I can't really tell...) silk organza (2,8), which is very thin and nice. Some of the ribbons/frills I treated with corn starch to stop them from fraying, because I didn't want to hem them to keep the whole cap "airy" despite its many decorations. It doesn't totally stop fraying, but it helps a little to keep the fibres together.
I didn't use a pattern, but if you want to use a commercial pattern, the base of the cap is close to JP Ryans Dormeuse/Baigneuse. All in all I used nearly 2 metres of fabric.
(yes, the wig is hilarious, I've written a tutorial about it...) :) http://hertzwerk-freiburg.blogspot.de/2015/10/1770s-big-hair-wig-tutorial.html