Arachne was a mortal woman (in some stories a princess, others a farmer's daughter) who was a gifted weaver. Not only was the finished product considered art, but the very act of watching her was something to see.
It was said that Nymphs would abandon their fun to watch her weave. Some commented that Minerva (Athena in Greek), the Goddess of crafts, must have taught Arache herself. Arachne was offended by this comment, and announced that she was a better weaver than Athena.
Athena was irritated at Arachne's claim, but decided to give the mortal a chance at redemption. She visited Arachne disguised as a crone and warned the woman not to offend the Gods. Arachne told Athena to save her breath, and that she welcomed a contest with Athena. And she also said that if she lost, she would accept any punishment Athena thought necessary.
Athena welcomed the challenge and revealed her true form. The nymphs shrank back in fear at the sight of the Goddess, but Arachne stood her ground. She had made her claim, and there was no backing down now.
The contest began as each sat before their loom. Athena began to weave the scene of her contest with Neptune (Poseidon in Greek) for the city of Athens. A beautiful scene developed , showing Poseidon and the salt water spring and Athena with an Olive Tree. The bystanders marveled at the work of the Goddess.
Arachne created a tapestry showing scenes of Zeus' infidelity. Leda with the swan. Europa with the bull. Dana and the golden rain shower. The mortal managed to make the scenes life-like.
Athena, even though she had respect for the mortal artist, was offended by the presumptuousness of her choice of subjects. Added to the anger of being challenged, Athena stood and tore Arachne's tapestry to pieces and destroyed the loom. Then she touched Arachne's forehead, making sure the mortal felt guilt for her actions. Arachne was ashamed, but the guilt was too great for her and she committed suicide.
Athena took pity on Arachne, especially because she didn't mean to drive the mortal to suicide. She brought Arachne back from Hades, but not as a human. Instead, Athena sprinkled her with the juices of aconite and transformed the woman into a spider.