Tex. Tax Code § 151.332

(a) There are exempted from the sales tax imposed by Subchapter C of this chapter the receipts from the sale of tangible personal property that has been manufactured, produced, made, or assembled exclusively by a person 65 years old or older and that is sold at a qualified sale. A sale under this section qualifies for the exemption only if it is made as a part of a fund-raising drive held or sponsored by a nonprofit organization created for the sole purpose of providing assistance to elderly persons. All of the net proceeds derived from sales made during the fund-raising drive must go to the organization, to the persons who manufactured, produced, made, or assembled the items sold, or to both. An organization created for the purpose of providing assistance to the elderly is entitled to conduct not more than four separate tax exempt fund-raising drives during each calendar year, and the aggregate number of days during a calendar year during which one or more tax exempt fund-raising drives may be held by the organization is 20. Any sale occurring after the end of the fourth separate fund-raising drive in a calendar year or after the 20th day on which a fund-raising drive is held in a calendar year is not exempted by this section.

(b) There are exempted from the taxes imposed by this chapter the use, storage, or other consumption in this state of tangible personal property by a purchaser at a sale exempted by this section.