Hong Kong companies all have signaturebooks. According to the query of relevant information, after the Hong Kong company registration is completed, the Hong Kong Registry will issue a green box containing the relevant documents for company registration and three seals: corporate seal, small round seal and long signature seal. . A signaturebook is a long seal, also called an English signature seal. The size is 57 x 22 mm, and the color is mostly purple or blue. It is usually engraved with representative words, indicates the company's name and has a signature line for the directors to sign.