These caps were known as bonnetter in Scandinavia and were the height of fashion from the middle of the 16th century. In fact, other types of headwear are rarely seen or mentioned. These bonnetts were clearly seen as a prerogative of the nobility and both Swedish and Danish sumptuary laws forbade women of the burgher class to wear them . Of course the laws in themselves, supported by other documentary evidence, are evidence that this type of cap was also worn outside the nobility. The embroidered bonnett probably evolved from the decorated hairnets worn in the first half of the century
Many examples of bonnetts can be found in Scandinavian and German portraits, for example this portrait of the Danish Queen Sophia, by the painter Hans Knieper.
Source: Wikimedia Commons
I will eventually make more noble costumes from the second half of the 16th century and wear this cap with them; it does not yet have a complete costume to go with it.