Finest Iranian rugs are weaving in Tabriz, which is due to high number of wales. The unit of wale number is knot.
In Tabriz, knots are counted in every 7 cm. Rugs are at least 12 and at most 80 knotted.
Knots are usually symmetrical and firmly tied by hook and double weft.
Tabriz loom or non-fixed loom is an invention of Tabriz people.
Their other carpet weaving tools are similar to other parts of Iran.
Tabriz loom is a simple frame, containing two beams (Sareh), which are attached to each other by "Doyan" or "Yanliq" (right bars).
For stabilizing the loom, two columns are used as supports. The attachment point of these columns with "Sareh" is called "Koulfeh".