The aim of the research is studying the relation between fabrics thickness and the elastic band on shrinkage, to achieve this aim two types of weft knitting fabrics (light, heavy), and three lengths (10,15,20) cm and three width (1, 3, 5) cm of elastic band were used, where the other factors were fixed for sewing and the samples were all fixed in an area of 30 cm, and the research was used The analytical experimental approach to achieve the objectives of the research, the weight of the square meter, the number of rows and columns and the thickness were calculated. The shrinkage ratio test in the length of the rubber band was performed, and then the results were analyzed statistically using T. test and LSD test for multiple comparisons. One of the most important results of the research was that it is preferable to use a rubber band 1 cm wide and (10, 15, 20) cm long with light knitted fabrics, while in the case of using rubber band a width (3, 5) cm and a length of (10, 15, 20) cm is recommended using it with heavy knitted fabrics, the researcher recommends making use of the research results in determining the different lengths and widths of the rubber band that are commensurate with the thickness of the fabrics and thus achieve the required quality of the clothing product.