Is it permissible to purchase new clothing during the period of the Three Weeks, between Shiba Asar Be’Tammuz and Tisha B’Ab?
Halacha allows purchasing new garments during the Three Weeks, but only until Rosh Hodesh Ab. During the nine days from Rosh Hodesh Ab through Tisha B’Ab, one may not purchase new clothing, even if he does not intend to wear the garment until after Tisha B’Ab, and even if he intends to give it to somebody else as a gift. It is also forbidden to have a tailor prepare a new garment, such as a custom-made suit or dress, during the nine days from Rosh Hodesh Ab through Tisha B’Ab.
There are, however, a number of exceptions to this rule. Hacham Ben Sion Abba Shaul (Jerusalem, 1923-1998) rules that "Begadim She’enam Hashubim" – garments which are not considered "important," or significant – may be purchased during the Nine Days. Hacham Ben Sion mentions stockings as an example of such a garment. Garments such as these may be bought throughout the Three Weeks, even after Rosh Hodesh Ab. Furthermore, if a certain garment is available on sale, and if one waits until after Tisha B’Ab he will have to pay a higher price for it, then he may buy the garment during the Nine Days in order to save money. Another exception is shoes that one needs to wear on Tisha B’Ab. It is forbidden to wear leather shoes on Tisha B’Ab, and one must therefore ensure to have non-leather shoes available. A person who did not purchase non-leather shoes before the Nine Days may do so during this period, and he may wear them for the first time on Tisha B’Ab.
It is permissible to have clothing or shoes fixed during the Nine Days. (As mentioned earlier, however, one may not have a new garment prepared during the Nine Days.) It is forbidden to knit, weave or do needlepoint during the Nine Days.
Summary: One may not purchase new clothes or have new clothes made from Rosh Hodesh Ab through Tisha B’Ab, but it is permissible during this period to have clothes fixed, purchase non-leather shoes for Tisha B’Ab, and purchase undergarments and the like. Purchasing new clothes is forbidden even if one intends to wear them only after Tisha B’Ab or to give them as a gift. One may purchase new garments if they will cost more after Tisha B’Ab. Knitting, crocheting and needlepoint are forbidden during the Nine Days. These restrictions do not apply before Rosh Hodesh Ab.