1. a. All types of sewing, knitting, crocheting, and weaving etc. are prohibited during the Nine Days. The reason for this is that when the Bet HaMikdash was destroyed not only was its foundation ruined, but the אבן השתיה — the foundation stone of the world was suspended. We are told that in the Holy of Holies קדש קדשים  of the Temple there was a foundation stone called the אבן השתיה  which was also a foundation of the world — it did not continue to function after the Hurban. Since the word שתי which refers to the lengthwise threads of yarn placed in a loom which are woven into fabrics is similar to the word שתיה therefore just as the אבן השתיה  was nullified, so too, the שתי of the loom. Maran writes that one should be strict regarding this halacha from Rosh Hodesh Av (and not only the Week of Tishah B’Av).

b. This prohibition of sewing applies whether sewing for yourself or for others and no distinction is made whether you are paid or not.

c. Mending clothing and the like are permitted.

d. A bride or groom (who does not have children) who is getting married after Tishah B’Av is allowed to have a new suit made.

e. A tailor or someone who has a factory that makes clothing should ask a Rabbi what to do during the Nine Days.

f. Sewing or weaving that is not done for clothing is permitted, e.g. weaving a basket or needlepoint.

2. a. One should be strict not to buy or wear new clothes or shoes that bring simhah. (In the week of Tishah B’Av it is mandatory).

b. We should not wear new clothing, even on Shabbat.

c. New clothing that do not bring much happiness may be worn or bought, however not during the week of Tishah B’Av.

d. An individual may purchase sneakers for Tishah B’Av if he needs them. However, he should wear them before Tishah B’Av so as not to wear them the first time then.