Historic European woven carpets in England at Axminster and from the French manufactories at Savonnerie and Aubusson, the latter which originally only produced tapestries, were created to produce Western style carpets to replace the demand for imported Persian rugs that were a highly prized and expensive commodity in Europe from the 16th century onwards. Most early French weavings are classed as carpets not rugs because their sizes exceed 9' x 12'. The French manufactories reached their heights in the 17th and 18th centuries. Savonnerie designs were exclusive to the royal court while Aubusson carpets catered to the aristocracy. Each manufactory was influenced by Persian rug designs, but both soon developed uniquely French compositions. Savonnerie carpets are often in shades of gold, blue and pink with pictorial fields featuring framed landscapes, floral and twining plants, classical urns, columns, medallions, architecture, and animals. Aubusson designs frequently appear in pastel shades with a central medallion and Renaissance-style floral, pastoral, and chinoiserie motifs. Savonnerie carpets are knotted and cut pile carpets woven on vertical looms. The knot used is called Ghiordes or Turkish knot; the oldest known rug knotting technique. Aubusson carpets are woven on horizontal (low-warp or basse-lisse) looms using a slit-tapestry technique with interlock (dovetailing) and shared warp joins. Slit-tapestry technique creates an opening or slit on vertical areas of color change. Slits were sewn shut after weaving (see Flat Weave). A third popular category of European rugs are Donegal carpets. Woven in Ireland from the 1890s until 2001, early examples borrowed traditional Persian motifs, but later designs were influenced by the British Arts and Crafts movement and Celtic Revival style. At some point during the company's history Donegal carpets were woven as reproductions in Iran, an interesting twist to the usual way carpet design inspiration moves east to west.