Carpet is a piled tapestry woven by seating (fixing) knots on a base (background) of wraps and wefts. In the following section, we will introduce each of these elements and explain their applications.
Wrap (Tar, Chelleh, Toon) : 
Set of yarn evenly and quite parallel to each other fastened vertically on the carpet loom and since they are bearing a high traction force, are usually selected of cotton type.
Wrap drawing (Chelleh-keshi) :
This is the process of stationing wrap fibers by wrapper on the carpet loom. Since wrap is the base and foundation of the carpet, wrapping can be considered as the most important and the most sensitive stage of carpet-weaving. In general, wrapping on different types of looms is performed via two procedures :
A)    Farsi Wrapping (Chelleh-Keshi Farsi) :

In this procedure, for the objective of wrapping, first the process of running wrap (chelleh-davani) is fulfilled in an open space i.e. the wraps are rolled around the bars stationed on the ground at required intervals along a particular direction and then after performing necessary computations, the prepared wrap while crossing from the top-loom is transferred to the carpet loom.

This procedure is employed differently in various regions however, the most common methods are Markazi, Kermani, and a combination of these two procedures.In the Markazi method, after stationing the wraps on the loom, excess wraps for the objective of down-drawing on the top-loom and as separate bundles are knotted together. In Kermani method, these excess wraps are sewed to the top loom, rolled around the top-loom shaft and as weaving progresses, the woven section is rolled around a shaft stationed underneath and the wraps are opened from above and around the top-loom and drawn towards the bottom. In the combined method, the wraps are prepared in the form of wrap running (Chelleh-davani) however, to station the wraps on the loom, the rotary procedure is employed.
B)     Turkish wrap drawing (Chelleh-keshi) : 

in this method wrap drawing is done by two individuals and they directly seat the wraps on the loom. This type of wrap drawing too is performed via two Tabrizi and Hamedani methods.

Weft :

These are the horizontal paralleled fibers which constitute part of the carpet’s base (background) that after each row are crossed amongst the wraps.Depending on their position (from above or crosswise from behind) or their thickness are categorized into the following types :

A)    Underneath weft (thick) : 
This type of weft is thicker than the thin weft (surface weft) and is passed in a crosswise and drawn fashion underneath the wraps.
B)     Surface weft (thin) :
It is crossed from above in an undulating manner and after going round the underneath and surface wraps, is stationed in a zigzagging form on the lower weft.

Methods of Weft Insertion in Carpet:
A)    Single weft : 
using a single weft in each row. This weft, as required, will be selected from thick or thin types.

B)     Double weft :
This method of wefting is performed dissimilarly in different regions.In wriggle textured (Lull-Baft) civic carpet, a thin weft and a thick weft are used, in flat-textured (Takht-baft) tribal carpets two thick wefts, in Turkmen regions (Tekkeh tribes) two thin weft, and in semi-wriggle carpets of Hamedan region two wefts of medium thickness are employed.

C)    Three wefts :
This method of wefting is mostly prevaltent in Ravar region of Kerman and surface, beneath, surface wefts are used respectively.

D)    Severel fold, one weft :
This method of wefting is employed in wriggle-textured carpet of Bijar, Qaen, and Sabzevar in which is common to use a thick weft in each row and a thin weft in every several rows.
Knot :
The rolling of carpet yarn or pile around the axes of beneath or surface wraps in a particular order is called knot. This is the basic function in carpet-weaving. Knots are classified as follows :

knoting way with hook
A)    Double Knot : 
A knot which occupies two (or more) cells (compartments) of the carpet map (chart).
B)     Whole knot : 
A knot which occupies a full-cell of the carpet map.
C)    Semi-knot :
In this type of knot, a half-cell of the map (transversally or longitudinally) is filled up.
D)    A quarter knot : 
In this type of knot, a quarter of a map’s cell is occupied.
E)     Complementary (decorative) knot : 
A type of knot that to perfectionate the map is used beside a complete knot. The last three types of knots are used in tableau carpets (spectacle carpets). Generally, in Persian carpet weaving, complete/whole knots are prevalent which are seen in the following two types :

 

 

symmetrical knot
1-     Symmetrical / Turkish Knot : 

Including types of right, left, superior an Ukermani knots. For this type of knotting hook is used.

left symmetrical
2-     A symmetrical / Farsi Knot : 

Including right, left and oblique U a symmetrical knots. For this type of knotting, only the toe fingers are used.

 
left nosymmetrical Right nosymmetrical
 

 
Weaving Mechanism
The angle between the upper and the lower (beneath and surface) wraps and procedure of using wefts necessate employing different mechanisms in carpet-weaving which are :

A)    Lool  (Wriggle) :
In this method of weaving, the surface and beneath wraps are, via weft tension draft, stationed at two completely different levels and an angle of about 80-120 is created between the wraps. This procedure is mainly employed in civic carpets.
B)     Nim-Lool (Semi-wriggle) :
In this method of weaving, compactness of surface wraps is lesser than in the first type and there is an angle of about 120o-170o between them and the weft is employed in a semi-tractioned state. This procedure is mainly used in the villages.
C)    Flat (Takht) :

In this method of weaving the surface and beneath wraps are almost stationed at the some level and make an angle of about 170 to 180 between themselves and they are often devoid of beneath (lower) weft. This procedure is mostly employed by the Turkmen, tribemen and the nomads.

 

 
Course Per cm :
Refers to the number of courses per 6.5 or 7 cm2 so that the higher this number, the more fine-textured will be the carpet.
Kilim-Weaving
Before starting to weave the tapestry and after completion of weaving, for the purpose of strength and to prevent falling of the woven course, kilim-weaving process is performed. Kilim-weaving in carpet is done as follows :

A)    Canvas / Farsi :
Single-fold and many-fold : In this type of kilim only thick weft is used in a way that in each course while creating a cross (sign of multiplication), the thick weft is passed over the cross. In the single-fold type, one-fold weft and in many fold type, multifold weft is used.
B)     Azari : Simple and wool-woven (Suf-baf) :
 in the simple type a mixture of thick and thin threads are employed and there is no need to create a new cross sign. In case of using knotted and prominent patterns in this type of kilim-baft, it is referenced as Azari Suf-baf.
In some carpets in order to prevent collapse of kilim-baf, and also to add to its beauty,, at the beginning and at the end of the tapestry chain is employed.
Side weaves (finish) and its types :
Side weaves are colored yarn or yarns wrapped around the longitudinal border of the carpet which add to the strength of these borders and depending on the number of yarn and the method of their embracing the end wraps, they assume different shapes :
A)    Parallel side-wave :
This procedure consists of parallel wrapping of single-colored threads around the wraps selected as side-weaves.
B)     Contrast (discordant) side–weaves : 
The side-weave yarns, while crossing through the wraps relevant to side-weaves, pass amid each other and this is usually done using two contrast colors; this type of side-weave is common in tribal carpets.
C)    Intersecting side-weaves :
Creating a cross sign manner by the side-weave yarns, due to up and down movements while wrapping around the side-weave wraps. Often, in this type of side-weave, two contrasting colors are employed in two different directions; this type of side-weave is used in tribal carpets as well.
D)    Multicourse side-weave :
In this type, the side-weave yarn is crossed through the wrap bundles intended to be used for side-weaves.
Preliminary polishing/shearing :

The objective of this operation, performed via shears /clippers, is to arrange and level up the woven courses; for this purpose, while considering the appropriate length, the excess thread is sheared. This is after weaving each course of the carpet, wefting and combing; the length of the yarn (fringes; piles) remained on the carpet’s serface, depends on
coarse or fine-textured weaving of the carpet as well as the weaving habits of the region. So that tribal and somewhat rural carpets have long piles and civic fine-textured carpets with higher course counts represent longer piles; in such carpets so to speak, as the piles become shorter, the features of the carpet become more exposed and visible.

Complementary stages :  
Principally, the woven carpet, before being presented to the market, passes the following stages :
Darkeshi:
The defected and oblique-headed carpet after being dragged down from the loom, through “ Darkeshi” or “Mikh-kessi” operations are rectified.
Dusting :

At this stage, by stroking the  carpet its dust is shaken down.
Ironing :
At this stage, with an iron of suitable temperature, the back of the carpet is ironed; in this manner, in addition to removing excess piles, the knots become compacted beside each other and this operation in turn, while arranging and putting in order of knots at the back of the carpet, decreases the possibility of the carpet’s becoming moth-eaten (improves moth proofing). In the past, they used to rub salt crystals (sodium chloride) on the back of the carpet which due to disturbing the insects, could decrease the moth-eating process.
Washing :

During the weaving operations the carpet may become dirty. In order to clean the carpet and impart lustre and lucidity to its colors after weaving, the carpet is washed up either by hand or through employment of mechanical instruments.Except in exceptional and necessary cases, the carpet should not be washed and even in such cases the carpet should be only washed with pure running water (at normal temperature) and with neutral detergents. To do so, ordinary soap powder or soap rot (drumsticks = Moringa oleifera) can be used. Prior to washing, removal of blotches (dry cleaning) may be required. Once again it is emphasised that the strong alkali, carbonate of soda, sodium hydroxide, and hydrosulfite should not be used. Following washing, the carpet should be rinsed, and after desiccation in a semi-humid condition it should be hanged and exposed to air until it dries up.

Final finishing (Polishing) : 
After completion of weaving and dragging down the carpet from the loom, and conducting the above said operations, it undergoes the final finishing. The purpose of this operation is to remove excess piles leveling and smoothing the pile finishing of the carpet’s background and completion of the preliminary finishing is performed on the whole carpet. This is perfomred either by hand, using special knives (cutters) or via machines equipped with blades.