Thread is a type of yarn used for sewing. It can be made out of many different materials including cotton, linen, nylon, and sil.Thread is made from a wide variety of materials. Where a thread is stronger than the material that it is being used to join, if seams are placed under strain the material may tear before the thread breaks. Garments are usually sewn with threads of lesser strength than the fabric so that if stressed the seam will break before the garment. Heavy goods that must withstand considerable stresses such asupholstery, car seating, tarpaulins, tents, and saddlery require very strong threads. Attempting repairs with light weight thread will usually result in rapid failure, though again, using a thread that is stronger than the material being sewn can end up causing rips in that material before the thread itself gives way.