D.C. Mun. Regs. tit. 17, § 2403
2403.1 Each notary public commissioned in the District shall file his or her official signature and an impression of his or her official seal with the Office of the Secretary of the District of Columbia.
2403.2 A notary shall keep an official seal that is the exclusive property of the notary. When not in use, the seal shall be kept secure and accessible only to the notary.
2403.3 The seal shall not be possessed or used by any other person, nor be used for any purpose other than performing lawful notarizations.
2403.4 An official notary seal shall include the following elements:
(a) The notary's name at the top, exactly as indicated on the commission;
(b) The words "Notary Public" in the center
(c) The words "District of Columbia" at the bottom
(d) The expiration date in the center
(e) A border in a circular shape no larger than 1.75 inches surrounding the required words.
2403.5 A notary public shall affix his or her official signature and official seal on every document notarized, at the time the notarial act is performed.
2403.6 An embossment inker shall be used in conjunction with the official seal, making the impression legible, permanent, and photographically reproducible.
2403.7 In the case that the document being notarized is made of a non-porous material, such as Mylar or a similar material to which standard ink will not adhere an embossed seal shall be used alone or in conjunction with a non-porous, permanent ink that dries through evaporation, which will adhere without smearing.
2403.8 Notaries public commissioned prior to December 15, 2010, may use an official seal that does not comply with Section 2403.4 provided that seal is made visible with an embosser inker and coupled with an expiration stamp on all notarizations.
2403.9 Notaries public commissioned on or after December 15, 2010, must obtain
an embosser that complies with Section 2403.4 upon being newly- or re-appointed.
SOURCE: § 1.6 of Regulation No. 73-13, approved May 24, 1973, 19 DCR 1147, 1148 (June 11, 1973), 25 DCRR § 1.6; as amended by Notice of Final Rulemaking 57 DCR 11739 (December 10, 2010).