Carpets today are woven the same way they were thousands of years ago. People who say that carpets must be produced by mechanical means are speaking out of ignorance; presumably they cannot imagine that so even a carpet can be produced by hand.
Rows of knots are tied on a foundation of warp and weft and become the pile. The warp runs along the length of the carpet and the fineness of the weave depends on its thickness and the proximity of the warps to one another.
When the rug is completed the ends form fringes which may be braided, tassled or secured in some such manner. The wefts pass under and over the warps from one side of the rug to the other. They are sometimes unpiled to allow them to be tightly packed to secure each row of knots.
The weaver’s instruments are simple and hand made. The yarn is cut off with a knife after the knot has been made. The weft and rows of knots are then packed together with a heavy iron comb-beter with handle. The newly woven part is smoothed with a strong steel comb before it is trimmed roughly while it is still in the loom. After the carpet has been removed from the loom it is given a final trim with shears and a razor like tool.
There are two basic knots: the Turkish (Ghiordes knot) and the Persian (Sehna knot).