Why is it necessary to consult the purpose of the test with a professional before requesting one?
Often the purpose of the expert test is wrong or incomplete.
A relatively common example: the client is unsure whether the signature is his or not, "it does look very similar" he says, "but I for sure did not sign the document" he adds.
If just the signature authenticity is requested, we may be making a big mistake, because the signature may well be authentic. Similarly you could say, and this would not be the first time, that you did not sign this document, which is currently being assessed by the courts.