Tex. Alcoholic Beverage Code § 101.46

Sec. 101.46. CONTAINERS OF LIQUOR: MINIMUM CAPACITIES. (a) Except as provided by Subsections (b), (c), and (d), no person may import, sell, or possess with intent to sell any liquor in a container with a capacity of less than 20 milliliters. A container of liquor offered for sale that has a capacity of less than six fluid ounces must substantially conform to the labeling requirements of the Bureau of Alcohol, Tobacco, and Firearms for larger containers in which liquor is sold. Holders of distiller's or rectifier's permits wishing to sell liquor bottled in containers of less than six fluid ounces to wholesalers must sell such containers of liquor to wholesalers in units of unbroken, sealed cases. Wholesalers shall sell liquor bottled in containers of less than six fluid ounces to package stores in units of unbroken, sealed cases.

(b) Subsection (a) does not apply to permittees or licensees while engaged in supplying mixed beverage permittees or passenger transportation permittees under Section 48.03 or 48.05, nor to the possession or sale of liquor by a mixed beverage permittee or a passenger transportation permittee under Section 48.03 or 48.05, but none of the permittees or licensees covered by this subsection may possess liquor in a container with a capacity of less than one fluid ounce.

(c) Subsection (a) of this section does not apply to liquor imported under Section 107.07 of this code.

(d) Spirit coolers, as described by the definition of "distilled spirits" in Section 1.04 of this code, may be sold in containers with a capacity of less than 355 milliliters as well as in containers with any other capacity authorized by this code for distilled spirits.