Blue dye came from woad, and later in period, also from indigo. A limited number of shades were possible. Because large quantites of woad plant needed to be grown, and then the product fermented and processed, it was not a cheap dyestuff in early period, however it was still cheaper than the bright purple dyes. Woad could be traded as balls of dried dyestuff quite easily in period, and thus could be found in places not suitable for the plant to grow in.
Sources of period recipes for blue dyes
- A Profitable Booke, 1586