<Li> Upholstery: These needles are heavy, long needles that may be straight or curved and are used for sewing heavy fabrics, upholstery work, tufting and for tying quilts; the curved variety is practical for difficult situations on furniture where a straight needle will not work Heavy duty 12" needles are used for repairing mattresses . Straight sizes: 3 "- 12" long, curved: 1.5 "- 6" long . </Li> <P> Needle size is denoted by one or more numbers on the manufacturer's packet . The general convention for sizing of needles, like that of wire gauges, is that within any given class of needle the length and thickness of a needle increases as the size number decreases . For example, a size 9 needle will be thicker and longer than a size 12 needle . However, the needle sizes are not standardized and so a size 10 of one class may be (and in some cases actually is) either thinner or finer than a size 12 of another type . Where a packet contains a needle count followed by two size numbers such as "20 Sharps 5 / 10" the second set of numbers correspond to the range of sizes of needle within the packet, in this case typically ten sharps needles of size 5 and ten of size 10 (for a total of 20 needles). As another example, a packet labeled "16 Milliners 3 / 9" would contain 16 milliners needles ranging in sizes from 3 to 9 . </P> <P> The first form of sewing was probably tying together animal skins using thorns and sharpened rocks as needles, with animal sinew or plant material as thread . The early limitation was the ability to produce a small enough hole in a needle matrix, such as a bone sliver, not to damage the material . Traces of this survive in the use of bodkins to make eyelet holes in fabric by separating rather than cutting the threads . A point that might be from a bone needle dates to 61,000 years ago and was discovered in Sibudu Cave, South Africa . A needle made from bird bone and attributed to non-humans, estimated to be around 50,000 years - old, was found in Denisova Cave . A bone needle, dated to the Aurignacian age (47000 to 41,000 years ago), was discovered in Potok Cave (Slovene: Potočka zijalka) in the Eastern Karavanke, Slovenia . Bone and ivory needles found in the Xiaogushan prehistoric site in Liaoning province date between 30,000 and 23,000 years old . Ivory needles were also found dated to 30,000 years ago at the Kostenki site in Russia . Flinders Petrie found copper needles at Naqada, ranging from 4400 BC to 3000 BC . Iron sewing needles were found at the Oppidum of Manching, dating to the third century BC . </P> <P> A form of needle lace named nålebinding seems to generally predate knitting and crochet by thousands of years, partly because it can use far shorter rough - graded threads than knitting does . </P>

What is the gauge of a sewing needle