What is the ruling on stuffing hair with wool or plastic to adorn it from the back of the head?

If the hair padding is at the back, and its style does not resemble that of disbelieving or immoral women, then there is no harm in it. Sheikh Ibn Uthaymeen was asked about adopting hairstyles from models and he replied that it is not permissible for a woman to style her hair in the manner of disbelieving or immoral women, due to the Prophet’s (peace be upon him) saying: "Whoever imitates a people is one of them." He advised avoiding magazines and hairstyles that encourage taking from disbelievers. As for placing hair padding on top of the head or gathering the hair in a bun on top of the head, this is forbidden according to some scholars.