Approximately 15cm square the apostille certificate is always black text on white paper. It is normally fixed to the back of the document to avoid obscuring the document.
It includes up to 10 pieces of information depending on what document the certificate is being attached to.
Note: Not all documents are signed or sealed. An example of this is a birth certificate. There is no signature or seal/stamp. The apostille is only issued on genuine registry certificates. Therefore sections 2, 3 and 4 will be left blank. This does not invalidate the certificate, it is standard practice under the Hague Convention.