Hand knotted rugs are also often called Oriental rugs. Many different types of handmade rugs are also frequently referred to as Oriental rugs, but not all of them really are — some designs are not hand knotted. Authentic versions have each thread of wool knotted by hand to form a design. Higher quality rugs will usually have more knots per square inch (about 6.45 square cm) than lower quality styles. Three of the most common types of hand knotted rugs are sculptured, Persian, and Nepal weave designs.
Sculptured weave hand knotted rugs typically have the thickest pile of all the Oriental rugs. Pile refers to the thickness of the wool that is used to create the rug. In sculptured rugs, some of the fibers are longer than the rest to add texture and height. These rugs often have a simple but colorful design, with the sculpting marking the points where colors change in the pattern.
Nepal weave designs are often noted for their subtle designs and colors. A rug may be monochromatic, or made from different shades of the same color, with sculpting added to highlight the design. Sculpting is achieved by tying some fibers shorter or longer than the rest — typically, one color or shade will be at a different height than another color to emphasize the patterns. This helps make the design more visible, especially in rugs that use few colors. Nepal weave is popular in many rugs being created today for contemporary decorating.
The most common hand knotted rugs are known as Persian weave. These rugs are usually the most intricately designed and often the most expensive choice. Many of the rugs are named for the city or area where the detailed pattern was first created. These can be short or long pile, which gives the rugs varying thicknesses.
Sometimes different types of handmade rugs are confused for hand knotted rugs. One way to tell the difference is to look at the back. Hand tufted rugs, sometimes also called hand hooked rugs, can look impressive and beautiful, but are made with a tufting tool that pushes the wool through the canvas, and there will often be a backing glued or sewn onto the rug. True hand knotted rugs are typically made from quality wool and have a natural fringe around the edge. Hand tufted rugs and other styles may have the fringe sewn or glued on.
Reversible handmade rugs are usually hand woven, but do not involve knotting. These are called flat weave rugs because they have no knots and no pile, with patterns that look the same on either side. These can have designs just as intricate as hand knotted versions. Flat weave rugs don't generally require as much work as hand knotted rugs, so they are often a less expensive — but still handmade — option.