Tex. Gov't Code § 618.007

If the seal of this state, a political subdivision of this state, or a department, agency, or instrumentality of this state or of a political subdivision of this state is required in the execution, authentication, certification, or endorsement of a public security, instrument of payment, certificate of assessment, or eligible contract, an appropriate authorized officer may authorize the printing, engraving, lithographing, stamping, or other placement of a facsimile of the seal on the document.