 Sibton grew rich on proceeds from various forms of husbandry, and from the wool trade which built so many grand English churches.Although Suffolk wool was not of the finest quality, according to some historians, often stained with tar or grease, it was nevertheless in great demand, particularly in East Anglia, which had many Flemish weavers anxious to convert it into exportable cloth.The abbey's various mills, of which there were at least 15 on their outlying Suffolk estates during the 13th century, both watermills and windmills, were maintained to mill grain on economic principles quite unlike those of later periods.