Collectors will spend lifetimes determining which Oriental rugs or carpets should be purchased. Finally what matters is taste and there is no right or wrong view. However, there are common criteria by which Oriental rugs are judged.
A good wool will feel reasonably soft to the touch, perhaps a little oily, can take heavy use and readily absorbs the dyes. A carpet or rug that is very soft is not durable – it is like buying a lower quality cashmere jumper which is lovely to touch but becomes easily worn. The slight oiliness is due to the lanolin in the wool and it resists stains acting as a barrier between the wool and stain. A poor wool is often scratchy, dry and unpleasant to the touch and may have kemp (grey hairs that are brittle).
Good rugs lie flat on the ground with the minimum of wrinkles or ripples along their edge to distract the eye.
The dyes should be of good quality to resist fading in natural light and will not bleed when exposed to water.
Older rugs must not have moth damage or undue tears or stains. However, it is more acceptable in a very old carpet for there to be some wear and tear with frayed or missing ends and edges.