Decomposition of a fabric
Decomposition consists in finding in a given tissue all the elements necessary for its reproduction as exact as possible: armor, chain count, reduction of weft, materials used, titles or numbers of the threads.

Decomposition of a fabric
The work of decomposition can be divided into two main parts:

1- The analysis of the tissue

2- The arrangement

Analysis of the tissue

To analyze a fabric, the following operations must be carried out successively:

- Find the armor, ie the crossing order of the warp yarns with the weft.
- Count the number of threads to the centimeter
- Multiply this number of threads by the given pattern to know the total number of threads
- Divide this number by 80 if you wish to express yourself in litters
- Indicate the remounting- Indicate the stitching of the comb
- Divide the total number of yarns by the number of tooth yarns to know the total number of teeth used of the comb
- Divide this number by the width to know the reduction of the comb, ie the number of teeth to the centimeter. If necessary, translate this reduction in the number of teeth per inch (1 inch Lyons = 2.707 cm)- Indicate the number of yarns making up the strands (selvedges) and their comb stitching- Count the reduction of the weft, ie the number of blows or picks to the centimeter.- Translate this reduction in number of strokes or picks per inch- Find the title or number of the materials used in warp and weft
We will indicate how to resolve each of these operations.

1- Find Armor - Finding armor is an operation whose result is always certain but requires a lot of patience, reasoning and precision in execution.Depending on whether the weave is produced by warp or weft effects, the method to be used must change.
If armor is produced by chain effects, as in taffeta, twill, satin, the search for armor must be done at the tissue and in the direction of the chain; For this purpose, after cutting the sample with a straight line and establishing a fringe of about 1 mm by scrolling a few threads, the operator uses a decomposition lens or simply a count and a tip Tapered or slightly curved punch at the end with which it can successively insulate each wire. The clearance of each of the threads is recorded on free paper or on cardboard drawing paper using the conventional signs used to indicate the fabrics.
Care must be taken to keep as a witness the yarn whose play has just been recognized in order to establish the position of the yarns of the next yarn in relation to those of the previous yarn. Thus, for example, in a satin of 7, examining with a magnifying glass the first thread under the punch, we see that this thread floats on 6 strokes and binds under the seventh. But if we examine the play of the second wire, we will see that this second wire also floats on 6 strokes and binds under the seventh, but it is no longer possible to determine the position of its binding In relation to that of the first wire, in other words to determine the disengagement or interruption, therefore, absolute rule: always keep the previous thread as a witness.
The operator must proceed in this way successively for each ful until he has found a thread playing the same game as the first. He thus obtained the armor and the number of wires as well as the number of blows composing the ratio of this armor.
It is also at this moment that one must recognize whether the chain is composed of single, double, triple, and so on.
The chain is said to be simple when each wire is formed of only one strand. The chain is said to be double when each yarn is composed of two parallel strands separating very clearly, two yarns which have been doubled at the warping operation and which consequently do the same play in the fabric. It is understood that a triple thread would be that formed of 3 threads assembled at warping and which would make the same play in the fabric.
If the armor is produced by weft effects, such as in the reps, the search for the weave must always take place at the tissue, but in the direction of the weft, ie l The operator must successively examine the play of each weft stroke with the warp threads, taking care, as with the armor chain effects, to always retain the previous stroke as a witness to the next stroke.
An essential condition for quickly and surely finding the weave of a fabric is to know how to light up. There is no need for intense light, as one might think, but we must look for the angle of light under which the warp threads or weft threads appear most clearly to the eye of the obeserator . Thus, for example, if we examine a taffeta fabric by placing the sample in such a position that the light rays arrive perpendicularly to the weft and consequently parallely to the warp, we shall clearly distinguish the weft but the Warp yarns will be poorly lit and we will have difficulty reading the crossing of these yarns with the weft. Reciprocally, if we place the sample in the position where the light rays arrive perpendicularly to the chain, then we will distinguish very clearly the wires, but the weft will be less illuminated. We may conclude that, for taffeta, the specimen should be placed in such a position that the direction of the warp or weft is at an angle of 45 ° with the light rays, but this is not a And it is necessary that the operator, for each kind of tissue, seek the angle of light under which he best distinguishes the crossing of the threads, this is a very important point for the success and rapidity of the " surgery.

2- Count the number of wires to the centimeter - This operation is done using a compass and a magnifying glass or simply with the Lyons wire-count whose field measures one centimeter on the big side and 1/4 of Inch (6.767 mm) on the small side.
The manner of counting the wires varies for each armor; we will give it in time and place, but it is important that the operation be done with great precision in order to reduce to its minimum the inevitable error which it entails.

3- Multiply this number by the given width - The width of a fabric is very variable, it is sometimes subordinate to the use to which the fabric is intended. The fabrics for dresses and confections are established in a width of 60 to 90 cm for narrow fabrics which are generally fabrics dyed in floats or in a width of 100 to 120 cm for wide fabrics, generally dyed in pieces . Most velvets are set in a width of 50 cm. The width of the upholstery ranges from 54 to 130 cm, etc., etc.
In all cases, the operation is a simple multiplication of the width expressed in cm by the number of threads per cm. If the preceding operation has not been accurately performed, it will be understood that the total number of threads may be distorted in more or less and that the error committed may modify to some extent the quality of the fabric and, Consequently, the cost price.
Thus, suppose that a fabric has 120 threads per cm, if by mistake the operator counted 128 in a width of 110 cm, we would have:
128 x 110 = 14,080 wires whereas the given type comprises only:120 x 110 = 13,200 wiresDifference: 800 threads

4- Divide the total number of threads by 80. We know that the span consists of 80 threads, so to express the number of threads in spans, it is enough to divide the number of threads by 80, if there is A fraction, this fraction is expressed in wires, the number of which is indicated by the remainder of the division.

Examples:
6,400 wires / 80 = 80 staves
3,860 wires / 80 = 48 litters 20 wires
10.060 dils / 80 = 125 staves 60 wires

Moreover, this way of expressing the number of threads in litters tends more and more to disappear and has its raison d'être only in the case where the warping has to be done on the warping machine, seen That the bag is generally composed of 40 threads, the warping machine has only to double the number of litters given to obtain the number of musettes to be woven. In mechanical warping, the most often composed of 400 yarns is the total number of yarns that make up the warp that is useful for the warping machine to calculate the number of yarns but not the number of yarns .

5- Indicate remounting - The number of hems (frames) needed to make a fabric depends on:
Armor, so for a fabric whose armor is taffeta, it takes 2, 4, 6 or 8 smooth, ie a number of even heddles. For a fabric whose armor is 8, it takes 8 or 16 heddles, and so on.From the count of the string, ie the number of threads per cm, based on a maximum of 15 to 20 meshes per cm on each bar. Thus, for a taffeta with 80 threads per cm, it is necessary to remount on 6 healds, which would give 80/6 = 13 meshes 1/3 cm on each heald.As to the type of remission to be employed, nothing indicates it in the tissue, we shall therefore refer to other rules which we shall study later.

6- Indicate the comb stitching - The comb stitching, ie the number of threads to be passed between each tooth, also depends on the armor, the number of heddles and the chain count on the basis of a Generally a minimum of 20 teeth per cm or 54 teeth per inch and a maximum of 30 teeth per cm or 80 teeth per inch. However, in some tissues we will descend below or we will climb above these accounts.
In general, in order to facilitate the passage of the broken wires during weaving, it is necessary, as far as possible, to have the comb stitching tuned with the resetting, that is to say that the number of tooth wires is a submultiple of the Number of healds. So an armor on 6 heddles will have to prick as much as possible to 2 or 3 threads tooth, armor on 8 beams with 2 or 4 wires ...

7- Divide the total number of wires by the number of tooth wires - This is a simple operation to know the number of pricked teeth.

8- Divide the total number of teeth stitched by the width - The result of this division gives the number of teeth per cm, ie the count of the comb. To translate it in inches, multiply by 2.707.

9- Indicate the number of yarns making up the cords and the stitching of the comb -

The armor of the cords is generally Gros de Tours, however, in some cases, they are woven with the same weave as the piece (body of the fabric) and Are distinguished only by a different color and the size of the wires which are double or triple hoops, in addition, the comb stitching is very often different from that of the piece.
After recognizing the double or triple quality found by scrolling the threads of the cord, count the number of threads and look for the stitching of the comb. For this purpose, the number of piece wires contained in a compass space, for example 24 wires, is counted, and then the number of wires contained in the same space, ie 36 wires, is counted in the cord; There is therefore a proportion of 24 pieces of yarn for 36 yarns of cord, or two yarn pieces for three yarns of cord, if the stitching of the workpiece has been established with 4 tooth threads, it is understood that that of the strings will have to Make to 6 wires. If the comparison has given 24 threads pieces for 24 dils in the cord, the comb stitching must be the same in the cords and in the piece, etc.
Another method is to measure the width of the cord and calculate how many teeth this width corresponds to, knowing the reduction of the comb used for the part.

Example: The width of a cord is 5 mm, the reduction of the comb of 24 teeth / cm, or 2.4 teeth / mm, the cord therefore comprises 2.4 x 5 = 12 teeth, if we assume 48 threads in the cord, The comb stitching will be 48/12 = 4 tooth wires.

10- Count the reduction of the frame - This operation can be done with the compass or with the help of the count-wire while operating on the side where the frame is the most apparent; Thus, in the chain effeffes armours the reduction must be counted backwards of the fabric, since at the place the weft is generally concealed. In a taffeta or other armor without back, the reduction can be counted indifferently on one side or the other. In a weft effect weave, the reduction will be best counted on the spot of the fabric.

11- Finding the title or number of the warp and weft materials - This operation differs according to the material in question. It will be subject to further study.