How to Authenticate a Signature

Acquire an authenticated sample signature of the autograph in question. If the signature is on a piece of memorabilia, contact an expert in collectable memorabilia, and ask if she has an authenticated signature by the same person. If you can not locate an expert, contact the owner of a collectable memorabilia shop. If the signature is located on a painting, contact art galleries, and see if they have paintings done by the same artist, that have been signed and authenticated. You may be able to view the painting, and the signature, at the art gallery.

Compare the two signatures. Note any differences between the one you know is authentic, and the one that has not yet been authenticated. Differences may include hesitation in the stroke, double writing and general structure. Use a microscope to compare the signatures in greater detail.

View the signature under a microscope. If the signature in question is made of paint, and is applied to a painting, the signature should be incorporated onto the painted background as if it were painted while the background was wet. If the signature appears to be slightly on top of the background, the signature may have been added later, and might be fake.

Submit a sample of the ink, or paint, used to create the signature, to a lab specializing in analyzing paints and inks. Ask the lab to determine how old the ink or paint is. Compare the age the lab provides with the supposed date of the signature. If the age does not match, the signature may be a fake.

Enlist the help of a professional appraiser. Ask the professional appraiser to look at the signature, and determine if it is authentic.